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Minnesota Stormwater Manual

Difference between revisions of "Minnesota Stormwater Manual test page 5"

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{{alert|This page is an edit and testing page use by the wiki authors.  It is not a content page for the Manual. Information on this page may not be accurate and should not be used as guidance in managing stormwater.|alert-danger}}
 
{{alert|This page is an edit and testing page use by the wiki authors.  It is not a content page for the Manual. Information on this page may not be accurate and should not be used as guidance in managing stormwater.|alert-danger}}
  
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=temp section=
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= =
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[[Summary of changes in Version 4 Minimal Impact Design Standards (MIDS) Calculator]]
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Operation and Maintenance of Bioretention and Other Stormwater Infiltration Practices 
  
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{{:Training and webinar schedule}}
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Overview of Typical O&M Issues
 +
Bioretention practices and other stormwater infiltration practices like rain gardens and infiltration trenches are vegetated landscape practices that capture, filter, and infiltrate stormwater runoff. In addition, these practices can provide ecosystem services such as nutrient cycling and storage, carbon sequestration, reduction in heat island effect, climate adaptation, and habitat for bees, butterflies, and other insects and small animals that pollinate. Bioretention and other infiltration practices may be subject to higher public visibility, greater trash loads, pedestrian traffic, vandalism, and vehicular loads, particularly in urban areas.
  
 +
These practices require dedicated and regular maintenance to ensure proper and long-lasting operation and ecosystem benefits. The most frequently cited O&M concerns for infiltration practices include:
 +
*Permanent standing water or flooding due to clogging caused by organic matter, fine silts, hydrocarbons, and algal matter. Clogging can occur at the surface, or in the inlet, outlet, or underdrain pipes.
 +
*Runoff bypasses the practice due to incorrect grading and slopes, or because the inlet is blocked.
 +
*Accumulation of trash and debris within the infiltration practice.
 +
*Insufficient/inadequate vegetation or overcrowded vegetation .
 +
*Inadequate pollutant removal due to improper soil media selection.
  
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[[Jeremy case study]]
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The sections below describe best practices to prevent or minimize these common problems.
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[[Raj case study]]
 
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[[Nick case study]]
 
  
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[[Jeremy temp page]]
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==Design Phase O&M Considerations==
 +
Designers should design bioretention and infiltration practices in ways that prevent or minimize O&M issues. Examples include:
 +
*Limiting the contributing drainage area and sizing the practice in accordance to its contributing drainage area to prevent flooding issues.
 +
*Providing pre-treatment and trash racks to prevent clogging or trash accumulation.
 +
*Providing a vegetation design plan, emphasizing native plantings (see Plants for Stormwater Design) to enhance pollinator and wildlife habitat, improve infiltration and evapotranspiration, reduce urban heat island effect, provide optimized carbon sequestration, and provide climate adaptation.
 +
*Specifying the optimized soil media composition and depth to effectively trap or sequester nutrients (phosphorus in particular), and that can also support the desired vegetation.
 +
*Providing educational signage to increase public awareness.
 +
*Installing measures like low fencing to prevent damage from pedestrian foot traffic .
  
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=Header=
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Designers should also recognize the need to perform frequent landscaping maintenance to remove trash, check for clogging, and maintain vigorous and healthy vegetation. Designers can incorporate design solutions to facilitate maintenance activities. Examples include:
 +
*Incorporating multiple and easy site access points
 +
*Installing observation wells
 +
*Providing recommendations of vegetation appropriate to the location
  
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Register for the wiki-Webex training: [https://minnesota.webex.com/minnesota/onstage/g.php?MTID=ee9e4f13be4b2ac0cf85c25b6e535f074]
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The designer should also provide a site-specific O&M plan that includes the following:
 +
*Construction inspection schedule and checklists
 +
*Post-construction routine maintenance schedule and checklists
 +
*Operating instructions for the practice (if applicable)
 +
Example O&M plans are provided further down.
  
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[[Minnesota Pollution Control (MPCA) Simple Estimator]]
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For more design information and criteria for individual infiltration practices, see the “design criteria for bioretention” or “design criteria for infiltration practices” pages.
 +
 +
Construction Phase O&M Considerations
 +
Proper construction methods and sequencing play a significant role in reducing O&M problems. Some key items during the construction phase include:
 +
#Before construction begins:
 +
##Ensure that the contributing drainage area is fully stabilized with vegetation prior to the beginning of construction. Also make sure that impervious areas in the contributing drainage area are clean.  If this is not possible, use barriers or diversions to direct stormwater flows from the contributing drainage area away from the practice.
 +
##Install any needed erosion and sediment controls in your construction site and prepare a storm water pollution prevention plan (SWPPP).
 +
##Designate a stormwater supervisor to make sure someone is responsible for erosion and sediment control.
 +
##Hold a pre-construction meeting with the designer and the installer to review the construction plans and the sequencing of construction.
 +
#During construction:
 +
##Construct any pre-treatment devices before constructing the main bioretention or infiltration system.
 +
##Ensure heavy equipment does not enter the footprint of the practice to avoid compaction of the infiltration medium.
 +
##Store any soil or gravel media downstream of the practice footprint to avoid clogging the infiltration medium. If this is not possible, store soil or gravel media in some type of covered or contained structure.
 +
##Inspect the practice during construction to ensure that the infiltration practice is built in accordance with the approved design and standards and specifications. This includes verification of the media composition and depths. Use a detailed inspection checklists that include sign-offs by qualified individuals at critical stages of construction, to ensure that the contractor’s interpretation of the plan is acceptable to the professional designer. Example construction phase inspection checklists are provided further down below.
 +
##Ensure that the plant and vegetation mix conforms to the vegetation design plan, particularly if the vegetation was selected to provide ecological function (such as pollinator habitat).
 +
#After construction:
 +
##Verify that the infiltration practice was built in accordance with the approved design and standards and specifications, including the pre-treatment devices as well as the main infiltration practice.
 +
##Verify that the contributing drainage area is fully stabilized with vegetation prior to removing any barriers, diversions, or erosion and sediment control measures.
 +
##Verify that the practice actually captures and infiltrates runoff. Conduct a full inundation test to inspect the underdrain and outflow function.
 +
##Verify that the practice reduces nutrient loads. Collect inflow and outflow storm water samples and have them analyzed for nutrient concentrations.
 +
##Use a detailed inspection checklist that includes sign-offs by qualified individuals at the completion of construction, to ensure that the contractor’s interpretation of the plan is acceptable to the professional designer. Example construction phase inspection checklists are provided further down below.
  
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[[Default TSS and TP loads for different land use scenarios using the MPCA Simple Estimator]]
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==Post-Construction Phase O&M==
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Effective short and long-term operation of bioretention and infiltration practices requires  dedicated and routine maintenance. Proper maintenance will not only increase the expected lifespan of the facility but will improve ecological function, aesthetics, and property value. Important post-construction considerations are provided below.  
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The objective of this analysis was to provide default estimates of annual loads of total phosphorus (TP) and total suspended solids (TSS), in pounds per acre, from stormwater runoff in Minnesota cities. Results may be used by cities where land use matches or approximates one of the land use scenarios in this analysis. The results represent estimated loads with no implemented best management practices (BMPs). Cities can then use the appropriate default Estimator spreadsheet to determine the TP and TSS reductions associated with BMP implementation.
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*A site-specific Operations and Maintenance Plan should be prepared by the designer prior to putting the stormwater practice into operation. This plan should provide any operating procedures related to the practices. The plan should also provide clear maintenance expectations, activities, and schedules. The O&M plan should also include an example O&M inspection checklist and an example maintenance report. Example O&M plans and inspection checklists are provided further down below.  
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*A legally binding and enforceable maintenance agreement should be executed between the practice owner and the local review authority. Example maintenance agreements are provided further down below.
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==Analysis==
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*Maintenance activities should be careful not to cause compaction or damage to the vegetation. No vehicles or stockpiling should be allowed within the footprint of the practice. Foot traffic should be kept to a minimum.
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We used the [https://stormwater.pca.state.mn.us/index.php?title=Guidance_and_examples_for_using_the_MPCA_Estimator MPCA Simple Estimator] (Estimator) to calculate average annual loading, in pounds per acre, for total phosphorus (TP) and total suspended solids (TSS). We used the default values in the Estimator for event mean concentration and runoff coefficient and assumed an annual average precipitation of 30.65 inches (Twin Cities Metro Area (TCMA)). These values are discussed in the Minnesota Stormwater Manual, as well as guidance for the MPCA Simple Estimator. Appropriate links include the following.
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*Maintenance activities should apply to all parts of the bioretention or infiltration practices, including the pre-treatment devices, the main bioretention/infiltration area, the vegetation, the media, and any conveyance or discharge pipes.  
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*Event mean concentrations for [https://stormwater.pca.state.mn.us/index.php?title=Event_mean_concentrations_of_total_and_dissolved_phosphorus_in_stormwater_runoff total phosphorus] and [https://stormwater.pca.state.mn.us/index.php?title=Event_mean_concentrations_of_total_suspended_solids_in_stormwater_runoff total suspended solids]
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*BMP areas generally should not be used as dedicated snow storage areas. Click here for additional snow and salt considerations.
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*[https://stormwater.pca.state.mn.us/index.php?title=Stormwater_runoff_coefficients/curve_numbers_for_different_land_uses Runoff coefficients]
 
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*[https://stormwater.pca.state.mn.us/index.php?title=Guidance_and_examples_for_using_the_MPCA_Estimator Guidance for the MPCA Simple Estimator]
 
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We gathered land use data for several TCMA cities using [https://lphonline.metc.state.mn.us/commportal Metropolitan Council land use data]. The land use categories for the Met Council data do not match those used in the Estimator, so we converted the Met Council data into land uses used in the Estimator. These are summarized in the following table. Because this is subjective, we include a column describing the relative significance of a specific land use to total acres in a city. For example, farmstead was assigned to agricultural land use. Farmsteads may not be associated with typical agricultural practices, but farmstead is a minor land use and therefore has a minor impact on overall pollutant loading.
 
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{{:Met Council and Manual land use categories}}
 
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The Estimator does not have default emcs and runoff coefficients for golf courses and extractive land use. We conducted a brief literature review to determine values for these two land uses. Default values for Estimator inputs are summarized in the following table.
 
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−
{{:Land use event mean concentrations (emcs) for the MPCA Simple Estimator}}
 
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−
[[file:Estimator default Figure 1a.png|400px|thumb|alt=figure default percent land use|<font size=3>Percent of total land use in specific land use categories for three groups. See text for description of groups. Click on image to enlarge.</font size>]]
 
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[[File:Estimator default Figure 2.png|400px|thumb|alt=Figure showing TP and TSS loading rates|<font size=3>TP and TSS loading rates, in lb/ac/yr, for different land uses. Note the log scale. Click on image to enlarge.</font size>]]
 
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We divided the selected cities into three groups, as described below.
 
−
#Group 1: St. Paul, Minneapolis, Brooklyn Park, Golden Valley, Edina, Bloomington, and Roseville. These are core TCMA cities and have been built out for several decades.
 
−
#Group 2: Woodbury, Eagan, Apple Valley, Andover, Maple Grove, Burnsville, and Lakeville. These are established suburbs that are largely built out, but have only reached this build out status in the past decade or two.
 
−
#Group 3: Chaska, East Bethel, Farmington, Hastings, Victoria, St. Francis, Prior Lake and Medina: These are outer ring suburbs that are undergoing development.
 
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−
Using the land uses from the Estimator and Met Council, we entered percentages for each land use for each city and converted these to fractions. If the fractions did not add to 1.0, we adjusted the fractions so that the total equaled 1.0. Thus, the data represent land use across one (1) acre within a specific city. We calculated means, standard deviations, and associated coefficients of variation (CV). We selected a sufficient number of cities to ensure the CV was less than 1 for each land use. CVs exceeded tolerance limits for agriculture in Group 1 and extraction in Group 3. Since these land uses make up a very small percent of the total land use for these two groups, we assumed the high variability would not significantly affect the results.
 
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The distribution of land uses for the three groups is shown in an adjacent figure. Residential land use decreases in importance from Groups 1 through 3, while open space and agriculture increase in importance. Commercial, industrial, institutional, and transportation decrease as a percent of total acreage from Groups 1 through 3, although these land uses each comprise a relatively small percent of total land use. Parkland is similar across the three groups, while water comprises a greater percent of land use in Group 3 compared to Groups 1 and 2.
 
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These land use distributions seem logical and have a significant impact on TP and TSS loading. The adjacent figure, which utilizes a log scale, shows that TP and TSS loading are much higher for developed land uses compared to open space and park. Also note that loading from agricultural land use is lower than from urban land uses. The default emcs and curve numbers used in the Estimator are the result of an extensive literature review, with the exception of agriculture, golf courses, and extraction. Golf courses and extraction are not important land uses, but agriculture is for Groups 2 and 3 and the Estimator may underestimate or overestimate contributions from agriculture.
 
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−
Average annual pollutant loads are shown for each Group in the adjacent table. The table includes values for a scenario where water was included in the calculation and a scenario where water was excluded.
 
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−
{{:Average TP and TSS loading rates for three land use groups}}
 
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−
==How to use these results==
 
−
The pollutant loads for each Group represent average annual loads, in pounds per acre, for TP and TSS. These are loads with no BMPs implemented and are based on default emcs, curve numbers, and precipitation values. The numbers may be used directly by cities, but cities should carefully read the next section on Notes to ensure these default conditions match the areas being modeled by the city. If the assumptions used in this analysis do not match conditions in the city or the area being modeled, appropriate values should be used in the Estimator to derive a value for the area being modeled.
 
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−
The files for the three groups can be accessed at the following links.
 
−
*Group 1: [[File:Group 1 analysis.xlsx]]
 
−
*Group 2: [[File:Group 2 analysis.xlsx]]
 
−
*Group 3: [[File:Group 3 analysis.xlsx]]
 
−
 
 
−
===Assessing pollutant reductions with BMPs===
 
−
To estimate pollutant reductions associated with implementation of best management practices (BMPs), follow these steps.
 
−
*Determine which group is applicable to your situation
 
−
*Open the Estimator file for that group
 
−
*Adjust inputs as appropriate.
 
−
**Average annual rainfall will likely require adjustment.
 
−
**Adjustments to emcs and runoff coefficients should be made only if local data support adjustments.
 
−
**Adjust acreages if appropriate, but '''make sure the total acreage equals one acre''' since the calculations are made on a per acre basis.
 
−
*Enter BMP information. '''This must be entered on a per acre basis'''. For example, if biofiltration practices (rain garden) are implemented in residential areas and residential areas comprise 50 percent of your area (Group 1), enter 0.10 as the biofiltration BMP acreage in Sections 3 and 4 of the Estimator (0.2 X 0.5).
 
−
*View results on the Summary Sheet in the Estimator
 
−
 
 
−
===Example===
 
−
Assume the default Group 1 condition. Assume biofiltration practices (rain garden) are implemented across 20 percent of the residential area. Residential area comprises 50 percent of the total area. Enter 0.1 (0.5 X 0.2) in cells B56 and B81 of the Estimator (biofiltration). Going to the Summary sheet, we see that TSS has been reduced by 11 lbs/ac/yr to 154 lb/ac/yr and TP has been reduced by 0.03 lb/ac/yr to 0.58 lbs/ac/yr.
 
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−
==Notes==
 
−
There are several considerations when using the above information as a surrogate for pollutant loading from a city. These are summarized below. Cities should carefully review these to ensure the conditions in their area of interest meet these conditions.
 
−
*Cities should determine if the recategorization of Met Council land uses is appropriate for their situation. In particular, undeveloped land should be assessed. It was categorized as open space for this analysis. Open space, as used in the Estimator, has very low pollutant loading rates. Some undeveloped land may not be appropriately categorized as open space. Examples include abandoned land that is compacted or has significant impervious surface, parking areas, and land on steep slopes with erodible soils.
 
−
*Agriculture encompasses a wide range of land uses, ranging from row crop to pasture. The default values used in the Estimator are not based on a rigorous literature review and agriculture is lumped into a single land use. Cities should carefully review the default values to ensure they are accurate. While the Manual does not provides a rigorous analysis, it does list several references for agricultural land uses and includes curve numbers for different types of agricultural land.
 
−
*Pollutant loading from residential areas, particularly phosphorus, is dominated by tree cover. In conducting our literature review of land uses, we did not feel there was sufficient data to divide residential land uses into subcategories. The Manual does, however, provide a discussion of how to adjust emcs based on tree canopy cover. The default emc for TP in the Estimator assumes 20 percent tree canopy cover.
 
−
*Transportation has very high pollutant loading per acre, but most studies focus on high traffic corridors. The Met Council data reflect this in using the category Major Highway. Thus, the default values for transportation in the Estimator represent these major transportation corridors.
 
  
  
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<!--
 
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[[Coir and applications of coir in stormwater management]]
 
  
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=Coir=
 
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This page provides information on coir. While providing extensive information on coir, there is a section focused specifically on stormwater applications for coir.
 
  
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==Overview and description==
 
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[[File:Coir fiber.jpg|300px|thumb|alt=image of coir fiber|<font size=3>A close-up view of coir fibre, by [https://commons.wikimedia.org/wiki/User:Fotokannan Fotokannan], licensed under CC CC BY-NC-SA</font size>]]
 
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Coconut (''Cocus nucifera'' L.) pith or coir, the mesocarp of the fruit, is a waste product that has potential benefits in growth media. Coir dust is peat-like and consists of short fibres (< 2 cm). Coir has a large surface area per unit volume, is hydrophilic, and therefore has the ability to absorb water. It's primary components are lignin and cellulose, each making up about 45% of coir's dry weight. Water soluble fractions typically account for about 5% of coir, by weight (Alam).
 
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−
There are three basic types of coir material.
 
−
#Coco pith is a rich, brown color and has a high water retention capacity.
 
−
#Coco fibers are stringy bundles that does not readily retain water and will break down over time.
 
−
#Coco chips are small chunks of coir that combine the properties of the peat and fiber. Coco chips retain water well and also allow for air pockets.
 
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−
Coir production involves separating the husk from the shelled nut and soaking the husk in water. The fibers are then separated from the pith and the resulting material is screened to create a uniform particle size. A dust is created during this process and the dust may be air dried and packaged. Prematurely harvested (green) fruits are often soaked in a saline solution to facilitate the separation process, which in turn affects the chemical properties of the resulting coir dust.
 
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Coir benefits may include but are not limited to the following.
 
−
*Coir has a neutral pH
 
−
*Coir improves water holding capacity of soil
 
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*Coir may improve drainage in fine-textured soils by creating pore spaces as it degrades
 
−
*Coir increases the organic matter content of soil, which can improve soil structure and aggregation
 
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*Coir production is sustainable and therefore does not contribute to greenhouse gas emissions.
 
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==Properties of coir==
 
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This section includes a discussion of chemical and physical properties of coir, and potential contaminants in coir,
 
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===Chemical-physical properties of coir===
 
−
The physical and chemical properties of coir vary with particle size. Noguera et al. (2003) varied particle size of coir dust, studying the properties of coir passing through sieves 0.125, 0.25, 0.5, 1.0, and 2.0 mm in diameter. They observed the following.
 
−
*As particle diameter increases, air content increased and water holding capacity decreased
 
−
*Electrical conductivity and micro-element concentrations were greatest in the smallest diameter coir
 
−
*Bulk density decreased from 0.122 to 0.041 g/cm<sup>3</sup> as particle size increased from <0.125 to >2 mm
 
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*Pore space increased from 92.3% to 97.3% as particle size increased from <0.125 to >2 mm
 
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*Water holding capacity (ml/l) decreased from 855 to 165, with the greatest change occurring with 0.5-1 mm particles
 
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*Shrinkage (volume loss on drying) decreased as particle size increased (38% to 15% as particle size increased from <0.125 to >2 mm)
 
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*Nutrient availability decreased with increasing particle size, but there were no significant differences between 0.125 and 2 mm. There was a large increase for the smallest particle size.
 
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Based on generally recommended plant specifications, the researchers concluded the 0.25-0.5 mm size appears most suited for plant growth, with some addition of larger particles recommended. Abad et al. (2005) similarly concluded that a mix of particle sizes is likely to be optimum for use of coir as a plant medium.
 
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Another factor affecting chemical properties of coir are the conditions under which it is prepared. In particular, if soaking in a saline solution is used in the preparation of coir, concentrations of potassium, sodium, chloride can be very high and may interfere with plant growth.
 
−
 
−
The following table summarizes data  from the literature on physical and chemical properties of coir. Some general conclusions include the following.
 
−
*Coir is slightly acidic but not as acidic as peat
 
−
*Available nitrogen, calcium, magnesium, iron, copper, and zinc are low, while phosphorus, sodium, chloride, and potassium are high, particularly if the coir was prepared in a saline solution
 
−
*Coir has a very high water holding capacity
 
−
*Coir has a high germination index compared to compost (Lodolini et al., 2017)
 
−
*Coir dust does not collapse when wet or shrink excessively as it dries (Cresswell)
 
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−
{{:Chemical and physical properties of coir}}
 
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−
===Potential contaminants in coir===
 
−
There are few concerns with contaminants in coir, with the possible exception of sodium and chloride in coir prepared using saline solutions. Levels of the elements may be at levels that negatively impact plant growth.
 
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−
Metal concentrations are well below Tier 1 Soil Reference Values. Organic contaminants, such as polycyclic aromatic hydrocarbons, are not a concern.
 
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−
==Effects of coir on physical and chemical properties of soil and bioretention media==
 
−
In this section we provide information on effects of coir on pollutant attenuation and the physical properties of soil and bioretention media.
 
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−
===Effects of coir on retention and fate of phosphorus===
 
−
There are limited studies on coir retention of phosphorus at concentrations typically found in stormwater runoff (less than 0.5 mg/L). Adsorption studies show that phosphorus adsorption at higher concentrations (greater than 1 mg/L) occurs through ion exchange and chemisorption being mechanisms for adsorption, with sulfate competing with phosphate for adsorption sites ).
 
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Shrestha et al. (2019) studied phosphorus leaching from columns containing mixtures of soil, compost, spent lime, and coir. Using tap water with no detectable phosphorus, they observed that adding coir (10% by weight) to a 70-20 soil-compost mix did not decrease phosphorus leaching compared to an 80-20 soil-compost mix. Similar results were observed for media with 40% compost. Hongpakdee and Ruamrungsri (2015) observed reduced phosphorus leaching at the flowering stage, possibly due to increased plant vigor and uptake in treatments containing coir. Herrera Environmental Consultants (2015) conducting flushing and leaching experiments for a variety of media mixtures, including mixtures containing coir. Mixtures of coir and granular activated carbon (GAC) or ash showed orthophosphorus concentrations of 0.021 and 0.052 mg/L, respectively, when flushed with solutions containing less than 0.004 mg/L. For leaching experiments, influent orthophosphate concentrations were 0.323 mg/L and effluent concentrations for coir-GAC and coir-ash mixtures were 0.025 and 0.164 mg/L, respectively. However, the researcher attributed retention of phosphorus to the GAC and ash rather than coir. The researchers also observed decreasing orthophosphorus leachate concentrations with time.
 
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Additional research is needed to understand the phosphorus retention or leaching from media containing coir. Research to date suggests coir will not retain phosphorus in stormwater runoff but will not significantly contribute to leaching from engineered media.
 
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===Effects of coir on retention and fate of other pollutants===
 
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There is limited research on retention and leaching of pollutants from coir. Shrestha et al. (2019) observed that media containing coir performed similar to spent lime for ammonium and nitrate retention and leached significantly less of these chemicals  than treatments containing compost. Herrera Environmental Consultants (2015) observed similar results and also observed that mixtures of coir and either granular activated carbon or ash reduced copper and zinc leaching compared to media mixtures consisting of just soil and compost. Because concentrations of potential pollutants are low in coir, leaching at concentrations of concern appears unlikely. An exception is coir that was soaked in salt water, which may contribute to high sodium, potassium, and chloride concentrations.
 
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===Effects of coir on soil physical and hydraulic properties===
 
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Coir has several properties that may improve soil physical and hydraulic properties (Cresswell; Noguera et al., 2003; Abad et al., 2005; Small et al., 2018; Lodolini et al., 2018; Arachchi and Somasiri, 1997).
 
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*Coir dust remains relatively hydrophylic (water attracting) even when it is air dry
 
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*Coir dust does not collapse when wet or shrink excessively as it dries
 
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*Increases water holding capacity
 
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*Increases soil porosity
 
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*Decreases soil bulk density
 
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===Effects of coir on soil fertility, plant growth, and microbial function===
 
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{| class="wikitable" style="float:right; border:3px; border-style:solid; border-color:#FF0000; margin-left: 10px; width:500px;"
 
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|-
 
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| style="text-align: center;"| '''Advantages of coir over peat (Source:Ministry of MSME, Government of India. 2016)'''
 
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|-
 
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| Requires lesser amount of lime due to high pH
 
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|-
 
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| Quick and easy rewetting after drying, while peat becomes hydrophobic on drying
 
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|-
 
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| Requires short time for irrigation to replace loss of water and drainage from pot, saving fertilizer due to non leaching of nutrients
 
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|-
 
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| Higher capillary wetting property
 
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|-
 
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| Able to provide aeration in base of mix
 
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|-
 
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| Very resilient and exceptional physical stability when wet or dried
 
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|}
 
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Pure coir is not suitable for plant growth. It has a high C:N ratio (>100) and a high lignin content, resulting in slow decomposition and immobilization of plant nutrients. In addition, polyphenols and phenolics acids in the coir can be phytotoxic and inhibit plant growth (Ministry of MSME, Government of India, 2016).
 
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When composted and added as an amendment to a growing media, coir improves plant growth, with coir outperforming peat in several studies. In the absence of composting, nitrogen and phosphorus additions will likely be necessary, depending on plant requirements. Calcium and magnesium additions may also be needed. Concentrations of other nutrients and micronutrients are generally acceptable for most plant species (Cresswell; Asiah et al., 2004; Noguera et al., 2003; Abad et al., 2002; Meerow, 1997; Lodolini et al., 2017; Hongpakdee and Ruamrungsri, 2015; Small et al., 2015; Scagel, 2003; Arachchi and Somasiri, 1997). Noguera et al. (2003) showed that, based on generally recommended plant specifications, 0.25-0.5 mm diameter coir particles appear most suited for plant growth, with some addition of larger particles recommended. Abad et al. (2005) similarly recommended a mix of particle sizes.
 
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==Standards, classification, testing, and distributors==
 
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===Coir standards and specifications===
 
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{| class="wikitable" style="float:right; border:3px; border-style:solid; border-color:#FF0000; margin-left: 10px; width:400px;"
 
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|-
 
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| colspan="2" style="text-align: center;"| '''Recommended values for coir used in a growth media (Source: see reference list in this section)'''
 
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|-
 
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| pH
 
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| 5.2 - 6.8
 
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|-
 
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| Electrical conductivity (ms/cm)
 
−
| 0.50 – 1.20 (lower part of range typically preferred)
 
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|-
 
−
| Cation exchange capacity (meq/100g)
 
−
| 20 - 40
 
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|-
 
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| Nitrogen (%)
 
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| 0.10
 
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|-
 
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| Phosphorus (%)
 
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| 0.01
 
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|-
 
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| Potassium (%)
 
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| 0.50
 
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|-
 
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| Copper (% minimum)
 
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| 1.5
 
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|-
 
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| C:N ratio (minimum)
 
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| 110
 
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|-
 
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| Lignin (%)
 
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| 30 - 35
 
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|-
 
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| Total organic matter (% minimum)
 
−
| 75
 
−
|-
 
−
| Moisture (%)
 
−
| 15 - 20
 
−
|-
 
−
| Ash content (%)
 
−
| 1.0 - 1.5
 
−
|-
 
−
| Impurities
 
−
| <3%
 
−
|-
 
−
| Fiber content
 
−
| <2%
 
−
|-
 
−
| Expansion
 
−
| > 12 l/kg
 
−
|-
 
−
| Water holding capacity
 
−
| 3-4 l/kg
 
−
|}
 
−
 
−
Recommended specifications for coir when used in a growing media include the following.
 
−
*Moisture content less than 20%
 
−
*Compression ratio 5:1
 
−
*pH 5.4-6.0
 
−
*Electrical conductivity less than 0.65 millimhos/cm (this ensures K, Na, Cl, Ca, and Mg contents are within acceptable limits)
 
−
*Not be more than two years old and should not be decomposed
 
−
*Golden brown in color
 
−
*Free from other contamination, sand and other foreign materials
 
−
*Free from weeds and seeds
 
−
 
−
Coir should be composted or incorporated into media containing a nutrient (N and P) source, such as compost. Alternatively, liming or addition of microorganisms may enhance decomposition of coir, which subsequently aids in release of nutrients from the coir. The Ministry of MSME, Government of India (2016) provide a discussion of different composting materials and methods, including specifications.
 
−
 
−
References containing specifications. Note that most of these references include information on the packaged material (e.g. bags, blocks, briquettes), such as weight and size.
 
−
*[http://www.coirexports-india.com/products/Product-Specification Coir Exports]
 
−
*[http://coirpith.co.in/Coirpithproduct.html Coir pith]
 
−
*[http://www.rudraexport.com/cocopeat.html Rudra]
 
−
*[https://www.reiziger.com/reiziger-coco-coir-pith/specifications/ Reiziger]
 
−
*[https://www.coco-peat.com/info/cocopeat-specifications Williams Enterprises]
 
−
*[http://coirboard.gov.in/wp-content/uploads/2016/07/Coir-Pith.pdf Ministry of MSME, Government of India]
 
−
 
−
===Distributors===
 
−
Distributors of coir for use in bioretention media (e.g. horticultural use) can readily be found on the internet and we do not make specific recommendations. When purchasing coir, the following questions should be asked.
 
−
*Were the husks loosened using fresh water or salt water?
 
−
*If salt water was used, has the coir been desalinized (e.g. residual salt washed out)?
 
−
*How was the coir dried (air or mechanical drying)?
 
−
*If the material was compacted (e.g. bricks), does it meet specifications (see above)?
 
−
*How long has the coir been left to mature (>6 months preferred)?
 
−
*Does the coir meet specifications described above?
 
−
*Has the coir been treated to prevent infestation?
 
−
*Has the material been sieved to achieve desired particle size distribution?
 
−
 
−
===Test methods===
 
−
Packaged coir is typically tested and meets specifications as described above. Standardized testing does not appear to exist for coir, but several methods for testing different characteristics appear to be appropriate.
 
−
 
−
The following references provide information on testing of coir.
 
−
*The [http://coirboard.gov.in/wp-content/uploads/2016/07/Coir-Pith.pdf Ministry of MSME, Government of India] (2016) provide a discussion of test methods for pH, moisture content, ash content, organic matter and organic carbon content, electrical conductivity, total nitrogen, phosphorus content, C:N ratio, and potassium content.
 
−
*[https://www.coco-peat.com/info/testing-methods Williams Enterprises] provides test methods for electrical conductivity, pH, moisture content, fiber content, impurities (sand), expansion or breakout volume, and water retention
 
−
*[http://www.evergreencoirs.com/testing.html Evergreen Coirs] provides test methods for electrical conductivity, pH, impurities (sand), expansion volume, moisture, and weed content
 
−
 
−
==Effects of aging==
 
−
Coir has a high C:N ratio, ranging from 75 to 186, with a median of 115 (Abad et al., 2002; Abad et al., 2005; Shrestha et al., 2019; Meerow, 1997; Arenas et al., 2002). It also contains a high lignin content and therefore decomposes relatively slowly unless nutrients, primarily nitrogen and phosphorus, are added to the media (Amlan and Devi, 2001). Composting is recommended to increase nutrient availability, which in turn may increase the rate of decomposition. Similarly, liming or addition of specific microorganisms can enhance decomposition (Prabhu and Thomas, 2002). Even when decomposition is facilitated, the life expectancy of coir exceeds two years (Newman 2007).
 
−
 
−
Prabhu and Thomas (2002) provide an extensive discussion of coir decomposition.
 
−
 
−
==Storage, handling, and field application==
 
−
*Store in a cool dry place
 
−
*Keep away from weedkillers and other garden chemicals
 
−
*If material is containerized, reseal after use
 
−
*Recommended application rates are 10-15 tons per hectare.
 
−
 
−
There are few handling concerns. Dust may be an eye irritant. Examples of material and safety data sheets can be found at the following links.
 
−
*[https://www.burpee.com/on/demandware.static/-/Sites-BURPEE-Library/default/v1576217273669/Images/Content/PDF/MSDS/Burpee_ecofriendly_natural&organicGardenCoir.pdf Organic garden coir]
 
−
*[http://www.synturf.org/images/pso110-m.pdf Coconut fiber]
 
−
*[https://www.amleo.com/images/art/PGH750-MSDS.pdf Fiber dust]
 
−
*[http://www.globalhort.com/pdf/MSDS/growingMedium/Coco%20Products%20-%20Coco%20Agro.PDF Coco coir]
 
−
*[http://www.ecofusion.net/datasheets/SDS%20-%20Coco%20Peat.pdf Coco peat]
 
−
 
−
==Sustainability==
 
−
Coir dust is a sustainable alternative to peat. Historically, very little coir has been utilized and has therefore been disposed as a waste. Prabhu and Thomas (2002), for example, estimated that in India alone, 1.5 million tonnes of coir pith could be obtained annually but only 500,000 were produced at the time of their study. More recently coir production in India has been estimated at about 1 million tonnes annually (Ministry of MSME, Government of India, 2016). Studies are underway to expand existing markets and develop technologies for manufacturing coir dust from coir fiber (Praveenkumar and Agamoorthi 2017; Varma, 2018).
 
−
 
−
==References==
 
−
*Abad, M., P. Noguera, R. Puchades, A. Maquieira, V. Noguera. 2002. ''Physico-chemical and chemical properties of some coconut coir dusts for use as a peat substitute for containerized ornamental plants''. Bioresource Technology. 82:241-245.
 
−
*Abad, M., F. Fornes, C. Carrion, V. Noguera, P. Noguera, A. Maquieira, R. Puchades. 2005. ''Physical Properties of Various Coconut Coir Dusts Compared to Peat''. Hort Sci. 40:7:2138-2144.
 
−
*Alam, F. An Overview of Coconut or Coir Fiber. Accessed from https://textilelearner.blogspot.com/2014/01/properties-of-coconutcoir-fiber.html on 2/13/20.
 
−
*Amlan, D., and L.S. Devi. 2001. [https://pdfs.semanticscholar.org/5518/efa1beb82f187062460c74f3951dfc5a17d7.pdf Effect of Organic and Inorganic Amendments on CO2 Evolution and Rate of Decomposition of Coir Dust]. Journal of Tropical Agriculture. 39:184-185.
 
−
*Anand, H.S., D. L. Suseela, and H.R. Nagaraju. 2002. [https://www.semanticscholar.org/paper/Chemical-and-biochemical-characterization-of-coir-Devi/f334def6bc1336c56200926fa0f2978bd083f07d Chemical and bio-chemical characterization of coir dust composts as influenced by pretreatment and enrichment]. 17th WCSS, 14-21 August, 2002, Thailand. Symposium 58, Paper 278. 6 p.
 
−
*Arachchi, L.P.V., and L.L.W. Somasiri. 1997. [https://www.semanticscholar.org/paper/USE-OF-COIR-DUST-ON-THE-PRODUCTIVITY-OF-COCONUT-ON-Arachchi-Somasiri/5ffef20b58ccdfda4a8c3273bf4e5f5c62b91fc7 Use of Coir Dust on the Productivity of Coconut on Sandy Soils]. Cocos. 12:54-71.
 
−
*Arenas, M., C.S. Vavrina, J.A. Cornell, E.A. Hanlon, G.J. Hochmuth. 2002. [https://www.semanticscholar.org/paper/Coir-as-an-Alternative-to-Peat-in-Media-for-Tomato-Arenas-Vavrina/19380f37eb86e5e1957f1cc20e2d0270d7adca77 Coir as an Alternative to Peat in Media for Tomato Transplant Production]. Hort Sci. 37:2:309-312.
 
−
*Asiah A., Mohd. Razi, I., Mohd, Khanif Y., Marziah M. & Shaharuddin M. 2004. [https://pdfs.semanticscholar.org/d8e6/64d378b1d38262f852bb7bc1b3fee2ec9729.pdf Physical and Chemical Properties of Coconut Coir Dust and Oil Palm Empty Fruit Bunch and the Growth of Hybrid Heat Tolerant Cauliflower Plant]. PertanikaJ. Trop. Agric. Sci. 27(2): 121 -133.
 
−
*Cresswell, G. [http://www.cocopeat.com.au/technical/productAnalysis/pdf/Cresswelldoc.pdf Coir Dust a Proven Alternative to Peat]. p 1-5. In: Proceedings of the Australian Potting Mix Manufacturers Conference, Sydney.
 
−
*Evans, M.R., S. Konduru, R.H. Stamps. 1996. Source Variation in Physical and Chemical Properties of Coconut Coir Dust. Hort Sci. 31:6:965-967.
 
−
*Herrera Environmental Consultants. 2015. ''Analysis of Bioretention Soil Media for Improved Nitrogen, Phosphorus, and Copper Retention – Final Report''. 340 p.
 
−
*Hongpakdee, P., and S. Ruamrungsri. 2015. [https://www.researchgate.net/publication/273521809_Water_Use_Efficiency_Nutrient_Leaching_and_Growth_in_Potted_Marigolds_Affected_by_Coconut_Coir_Dust_Amended_in_Substrate_Media Water Use Efficiency, Nutrient Leaching, and Growth in Potted Marigolds Affected by Coconut Coir Dust Amended in Substrate Media]. Hort. Environ. Biotechnol. 56:1:27-35
 
−
*Kumar, P., S. Chand, and V.C. Srivastava. 2010. [https://www.researchgate.net/publication/238136474_Phosphate_Removal_from_Aqueous_Solution_Using_Coir-Pith_Activated_Carbon Phosphate Removal from Aqueous Solution Using Coir-pith Activated Carbon]. Separation Science and Technology. 45:1-8.
 
−
*Lodolini, E.M., F. Pica, F. Massetani, and D. Neri. 2017. [https://www.researchgate.net/publication/312384600_Physical_Chemical_and_Biological_Properties_of_some_Alternative_Growing_Substrates Physical, Chemical, and Biological Properties of Some Alternative Growing Substances]. International Journal of Soil Science. 12:1:32-38.
 
−
*Meerow, A. 1997. [https://www.researchgate.net/publication/239530350_Coir_Dust_A_Viable_Alternative_to_Peat_Moss Coir Dust, A Viable Alternative to Peat Moss].
 
−
*Ministry of MSME, Government of India. 2016. [http://coirboard.gov.in/wp-content/uploads/2016/07/Coir-Pith.pdf Coir Pith, Wealth from Waste, a reference]. India International Coir Fair, July 15-18, 2016. 110p.
 
−
*Namasivayam C., D.Sangeetha. 2004. ''Equilibrium and kinetic studies of adsorption of phosphate onto ZnCl2 activated coir pith carbon''. Journal of Colloid and Interface Science.  280:2:359-365
 
−
*Newman, J. 2007. Core facts about coir. Nursey Management. https://www.nurserymag.com/article/core-facts-about-coir/ accessed 12/18/20.
 
−
*Noguera, P., M. Abad, R. Puchades, A. Maquieira, and V. Noguera. 2003. ''Influence of Particle Size on Physical and Chemical Properties of Coconut Coir Dust as Container Medium''. Communications in Soil Science and Plant Analysis. 34:3/4:593-605.
 
−
*Prabhu, S.R., and G.V. Thomas. 2002. [https://www.researchgate.net/publication/272481596_Bioconversion_of_coir_pith_into_value_added_organic_resource_and_its_application_in_agri-horticulture_Current_status_prospects_and_perspective Biological conversion of coir pith into a value-added organic resource and its application in Agri-Horticulture: Current status, prospects and perspective]. Journal of Plantation Crops. 30:1:1-17.
 
−
*Scagel, C.F. 2003. [https://www.researchgate.net/publication/43275179_Growth_and_Nutrient_Use_of_Ericaceous_Plants_Grown_in_Media_Amended_with_Sphagnum_Moss_Peat_or_Coir_Dust Growth and Nutrient Use of Ericaceous Plants Grown in Media Amedned with Sphagnum Moss Peat or Coir Dust]. Hort Sci. 38:1:46-54.
 
−
*Shrestha, P., M. T. Salzl, I. J. Jimenez, N. Pradhan, M. Hay, H. R. Wallace, J. N. Abrahamson and G. E. Small. [https://www.mdpi.com/2073-4441/11/8/1575 Efficacy of Spent Lime as a Soil Amendment for Nutrient Retention in Bioretention Green Stormwater Infrastructure]. Water 2019, 11(8), 1575
 
−
*Small, Gaston E , Wihlm, Spencer E , Wallace, Hannah R , Abrahamson, Jenna N , Deile, Madison P , Mahre, Erin K , Fischer, John PH , Jimenez, Ivan J , Shrestha, Paliza , Salzl, Michael T. ''Final Report: Soil Amendments for Enhanced Phosphorus Retention: Implications forGreen Infrastructure Design''. Accessed at https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/10938/report/F on 2/13/20.
 
−
*Varma, M.S. 2018. NCRMI’s pith technology to boost coir exports. Financial Express. Accessed at https://www.financialexpress.com/market/commodities/ncrmis-pith-technology-to-boost-coir-exports/1310190/ on 12/18/20.
 
−
-->
 
−
 
−
 
−
<!--
 
−
==Applications for biochar in stormwater management==
 
−
Biochar has several potential applications for stormwater management. Below is a brief review of what we know about biochar.
 
−
*Biochar increases water holding capacity of soil, improves aggregation in fine-textured soils, increases saturated hydraulic conductivity in fine- and medium-textured soils, and decreases hydraulic conductivity in very coarse-textured soils.
 
−
*Improve the fertility of nutrient-poor soils. In nutrient-poor soils, biochar appears to consistently improve nutrient cycling and availability for plants. Results for other soils are mixed and depend on the biochar and soil characteristics.
 
−
*Biochar generally improves retention of metals and PAHs.
 
−
*Results for bacteria and pathogens are mixed, but some studies indicate increased retention, primarily associated with straining resulting from increased surface area and micropore structure in biochar-amended soils.
 
−
*Biochar is likely to have limited effects on phosphorus retention unless specifically amended to retain phosphorus.
 
−
 
−
Possible implications for stormwater management include the following.
 
−
#'''Engineered media'''. Biochar incorporated into engineered media can increase water retention and infiltration. Low-nutrient biochars (e.g. wood-based versus manure- or sludge-based) produced at relatively low temperatures (less than 600<sup>o</sup>C) can improve phosphorus retention. Biochar may enhance nutrient cycling and improve fertility in media with relatively low nutrient concentrations (e.g. media mixes having lower fractions of compost).
 
−
#'''Contaminant hotspots'''. Biochar can be incorporated into treatment practices in areas with high or potentially high concentrations of metals and organic pollutants.
 
−
#'''Turf amendment/soil compaction'''. Biochar can added to turf or compacted media to improve hydraulic performance and nutrient cycling.
 
−
#'''Filtration practices'''.  Biochar can be used alone or mixed with other components for stormwater filtration applications, including but not limited to the following:
 
−
##Filtration media in new treatment systems, especially roof downspout units and aboveground vaults;
 
−
##Supplemental or replacement media in existing treatment systems such as sand filters;
 
−
##Direct media addition to a stormwater storage vault ;
 
−
##Direct application in bioretention or swale systems;
 
−
##Filtration socks and slings;
 
−
##Hanging filters in catch basins.
 
−
#'''Underground infiltration basins and trenches'''. Many underground infiltration practices are constructed in very coarse textured soils that may have limited ability to retain pollutants. Biochar can reduce infiltration rates and adsorb pollutants in these systems.
 
−
#'''Climate-related effects'''. While not specifically a stormwater objective, biochar incorporated into stormwater practices can sequester carbon and reduce nitrous oxide emissions.
 
−
 
−
{{:Potential biochar stormwater applications}}
 
−
 
−
Further reading
 
−
*[https://pprc.org/wp-content/uploads/2014/08/Emerging-Stormwater-BMPs_Biochar-as-Filtration-Media_2014.pdf Emerging Best Management Practices in Stormwater: Biochar as Filtration Media] - Pacific Northwest Pollution Prevention Resource Center
 
−
*[Ihttps://www.deeproot.com/blog/blog-entries/improving-stormwater-control-measure-performance-with-biochar Improving Stormwater Control Measure Performance with Biochar] - Deeproot
 
−
*[http://onlinepubs.trb.org/onlinepubs/IDEA/FinalReports/Highway/NCHRP182_Final_Report.pdf Reducing Stormwater Runoff and Pollutant Loading with Biochar Addition to Highway Greenways] - Final Report for NCHRP IDEA Project 182
 
−
*Mohanty et al. (2018)
 
−
 
−
==Effects of feedstock and production temperature==
 
−
Although the basic structure of all biochars is similar, the physical-chemical properties of biochar varies with the source material and with the temperature used in production.
 
−
 
−
===Effect of feedstock (source material)===
 
−
Since a wide variety of organic material can be used to produce biochar, it is not feasible to discuss each material separately. We provide the following general conclusions. Literature used to develop these conclusions is provided at the end of this section.
 
−
*Compared to wood derived biochar, non-wood feedstock such as grass, sludge, and manure yields biochar with fewer aromatic but more aliphatic groups and higher ash content. Greater concentrations of aliphatic compounds are associated with more reactive biochar.
 
−
*Manure- and sludge-based biochar contains higher concentration of nutrients than wood-based biochar and are therefore more likely to be a source of nutrient leaching.
 
−
*Manure- and sludge-based biochar attenuate metals more than wood based biochars
 
−
*Biochar parameters most affected by feedstock properties are total organic carbon, fixed carbon, and mineral elements of biochar. Feedstocks such as sawdust, wheat straw, and peanut shell have higher carbon concentrations than feedstocks such as manure, sludges, and waste paper.
 
−
*Capacity for carbon sequestration is primarily affected by feedstock, with higher carbon compounds having greater sequestration capacity.
 
−
*High ash biochars, such as manures and coffee husk, exhibit higher cation exchange capacity, which may increase nutrient capture, although high initial nutrient concentrations may offset this and even contribute to nutrient loss.
 
−
 
−
The [https://biochar-international.org/wp-content/uploads/2019/11/IBI_Biochar_Standards_V2.1_Final1.pdf International Biochar Initiative (see Appendix 6)] proves a classification system for biochar feedstocks, shown below.
 
−
*Unprocessed Feedstock Types
 
−
**Rice hulls & straw
 
−
**Maize cobs & stover
 
−
**Non-maize cereal straws
 
−
**Sugar cane bagasse & trash
 
−
**Switch grass, Miscanthus & bamboo
 
−
**Oil crop residues e.g., sugar beet, rapeseed
 
−
**Leguminous crop residues e.g., soy, clover
 
−
**Hemp residues
 
−
**Softwoods (coniferous)
 
−
**Hardwoods (broadleaf)
 
−
*Processed Feedstock Types
 
−
**Cattle manure
 
−
**Pig manure
 
−
**Poultry litter
 
−
**Sheep manure
 
−
**Horse manure
 
−
**Paper mill sludge
 
−
**Sewage sludge
 
−
**Distillers grain
 
−
**Anaerobic digester sludge
 
−
**Biomass fraction of MSW – woody material
 
−
**Biomass fraction of MSW – yard trimmings
 
−
**Biomass fraction of MSW – food waste
 
−
**Food industry waste
 
−
 
−
'''Literature'''
 
−
*Zhaoa et al. (2013) examined cow manure, pig manure, shrimp hull, bone dregs, wastewater sludge, waste paper, sawdust, grass, wheat straw, peanut shell, Chlorella, and water weeds
 
−
*Rimena et al., (2017) examined wood-based biochars (eucalyptus sawdust, pine bark), sugarcane bagasse, chicken manure, and coffee husk
 
−
*Jindo et al. (2014) examined rice husk, rice straw, apple tree wood chips, and oak tree wood chips
 
−
*Mohanty et al. (2018) provide an extensive discussion and literature review of different feedstocks and associated biochar properties
 
−
*Gai et al. (2014) studied twelve biochars produced from wheat straw, corn straw, and peanut shell
 
−
*[https://biochar-international.org/biochar-feedstocks/ International Biochar Initiative] provide a general discussion of feedstocks
 
−
*Conz et al. (2017) studied poultry litter, sugarcane straw, rice hull and sawdust
 
−
*[https://extension.tennessee.edu/publications/Documents/W829.pdf Jahromi and Fulcher] studied biosolids and green waste, corn straw and rice straw, gasifed rice hulls, hardwood, pelleted agricultural or forestry residues, switchgrass, and timber harvest residues
 
−
*Zhao et (2019) studied sewage sludge, agriculture biomass waste, and wood biomass waste
 
−
 
−
===Effect of production temperature===
 
−
Changes in the properties of biochar result from loss of volatile organic matter as temperature increases. This leads to a gradual loss in the number of functional groups on the biochar and increased aromaticity as temperature increases.
 
−
 
−
In general, the following conclusions are applicable for biochar used in stormwater applications.
 
−
*If retention of nutrients and most pollutants is desired, biochars produced at temperatures less than 600<sup>o</sup>C should be selected
 
−
*If the goal is to improve soil physical or hydraulic properties biochars produced at temperatures greater than 600<sup>o</sup>C should be selected
 
−
 
−
The following information comes from a literature review of the effects of production temperature on biochar
 
−
*Biochar yield and contents of N, hydrogen and oxygen decrease as pyrolysis temperature increases from 400˚C to 700˚C
 
−
*pH and contents of ash and carbon increase with greater pyrolysis temperature.
 
−
*Particle size and porosity increase with greater pyrolysis temperature.
 
−
*Hydrophobicity increases with greater pyrolysis temperature.
 
−
 
−
'''Literature'''
 
−
*Mohanty et al., (2018)
 
−
*Zhaoa et al., (2013)
 
−
*Klasson, (2017)
 
−
*Zhao et al., (2017)
 
−
*Jindo et al., (2014)
 
−
*Wang et al., (2018)
 
−
*Rimena et al., (2017)
 
−
*Lyu et al. (2016)
 
−
*Gai et al.. (2014)
 
−
*Conz et al. (2017)
 
−
 
−
==Properties of biochar==
 
−
This section includes a discussion of chemical and physical properties of biochar, and potential contaminants in biochar, .
 
−
 
−
===Chemical-physical properties of biochar===
 
−
The properties of biochar vary depending on the feedstock and production temperature, as discussed above. Consequently there is considerable variability in the chemical and physical properties of different biochars. The table below summarizes data from our literature review. Some conclusions from the literature are summarized below.
 
−
*'''Biochar has a large surface area.'''
 
−
*'''Cation exchange capacity (CEC) decreases as pyrolysis temperature increases'''. This is due to the loss of volatile organic content and associated functional groups as temperature increases. As CEC decreases, the ability of biochar to retain negatively charged chemicals, such as phosphate, decreases.
 
−
*'''Non-wood vegetative feedstocks have a greater CEC than wood feedstocks.''' This is due to a greater percentage of aliphatic compounds and associated functional groups. Non-wood feedstocks primarily consist of grasses.
 
−
*'''Sludges and manure-based biochars have high nutrient content and are thus not satisfactory for managing stormwater'''
 
−
 
−
{{:Chemical and physical properties of biochar}}
 
−
 
−
===Potential contaminants in biochar===
 
−
Potential contaminants associated with biochar are a function of the source material and production temperature. Of greatest concern are metals and polycyclic aromatic hydrocarbons (PAHs). Oleszcuk et al. (2013) examined metal and PAH concentrations in four biochars (elephant grass, coconut shell, wicker, and wheat straw). Metal concentrations (mg/kg) in the biochars are summarized below. Tier 1 Soil Reference Values (SRVs) are included in parentheses.
 
−
*Cd: 0.04-0.87 (25)
 
−
*Cu: nd-3.81 (100)
 
−
*Ni: nd-9.95 (560)
 
−
*Pb: 20.6-23.7 (300)
 
−
*Zn: 30.2-102.0 (8700)
 
−
*Cr: nd-18.0 (44,000 for CrIII; 87 for CrVI)
 
−
 
−
Concentrations in biochar are well below Tier 1 SRVs.
 
−
 
−
In the study by Oleszcuk et al. (2013), total PAHs ranged from 1124.2 ng/g to 28339.1 ng/g. The dominant group of PAHs were 3-ring compounds which comprised 64.6% to 82.6% of total PAHs content. The primary compounds included, in order of abundance, phenanthrene, fluorene, anthracene, and pyrene. No 6-ring PAHs were observed. Concentrations of PAHs and other organic contaminants, such as dioxins, decreases with increasing pyrolysis temperature (Lyu et al., 2016).
 
−
 
−
In general, biochars mixed with soil do not inhibit germination or root growth. Biochar may enhance soil fertility by providing nutrients or more commonly by slowing the release of nutrients from materials such as compost. was observed. Toxic effects have been observed for some invertebrates, indicating that in sensitive environments, biochar testing is advisable (Oleszcuk et al., 2013; Getz et al., 2018; Flesch et al., 2019; Wang et al., 2017) .
 
−
 
−
==Effects of biochar on physical and chemical properties of soil and bioretention media==
 
−
In this section we provide information on effects of biochar on pollutant attenuation and the physical properties of soil and bioretention media.
 
−
 
−
===Effect of biochar on retention and fate of phosphorus===
 
−
<div style="float:right">
 
−
<table class="infobox" style="border:3px; border-style:solid; border-color:#FF0000; text-align: right; width: 300px; font-size: 100%">
 
−
<tr>
 
−
<td>'''Biochar is not likely to provide significant phosphorus retention in bioretention practices unless impregnated with cations (e.g. magnesium) during production at relatively low temperatures (e.g. less than 600<sup>o</sup>C.)'''
 
−
</td>
 
−
</tr>
 
−
</table>
 
−
</div>
 
−
 
−
Biochar may have several properties for managing stormwater, such as increased water and pollutant retention, improving soil physical properties, and attenuating bacteria and pathogens. Biochar has been examined as a potential amendment to engineered media in bioretention or other stormwater control practices. With respect to phosphorus, information from the literature is mixed. Below are summaries from several studies.
 
−
*Mohanty et al. (2018) observed that biochar does not absorb phosphate efficiently. Phosphorus retention can be enhanced by impregnating biochar with cations such as magnesium and zinc.
 
−
*Reddy et al. (2014) found that biochar reduced influent phosphate concentrations by 47% in column experiments. Influent concentrations were 0.57 and 0.82 mg/L for unwashed and washed biochar, respectively. These concentrations are on the high end of concentrations found in urban stormwater.
 
−
*Yaoa et al. (2011) observed retention in biochar-(sugar beet source)amended soils that were fertilized. Adsorption was dominated by magnesium oxides and maximum adsorption occurred at pH values less than 4.
 
−
*Zhaoa et al. (2013) studied different feedstocks and observed high phosphorus concentrations in animal-based feedstocks and wastewater sludge (0.065 - 0.44%) compared to other feedstocks (0.007 - 0.07%)
 
−
*Iqbal et al. (2015) examined leaching of phosphorus from compost (80% yard and 20% food waste) and co-composted biochar (100% fir-forest slash). They found biochar amendments did not significantly reduce the leaching of phosphorus compared to the compost only treatment. Phosphorus leached from biochar, but because phosphorus concentrations in biochar are low, this leaching contributed little total phosphorus. Leached phosphorus was primarily in the form of orthphosphate.
 
−
*Han et al. (2018) found that addition of biochar to soil led to increased desorption of phosphorus during winter freeze-thaw cycles.
 
−
*Soinne et al. (2014) observed no effect of biochar on phosphorus retention in a sandy and two clay soils.
 
−
 
−
===Effect of biochar on retention and fate of other pollutants===
 
−
*'''Nitrogen'''. Biochar effects on nitrogen retention depend on the properties of the biochar and stormwater runoff. Biochars produced at relatively low temperatures (less than 600<sup>o</sup>C) provide some retention of organic nitrogen and ammonium nitrogen in stormwater runoff. Mechanisms for nitrogen retention include adsorption of ammounium and nitrogen immobilization. Leaching of nitrogen may decrease due to increased water holding capacity (Iqbal et al., 2015; Gai et al., 2014; Zheng et al., 2013; Ding et al., 2010).
 
−
*'''Metals'''. Biochar enhance retention of metals in stormwater runoff. (Reddy et al., 2014; Domingues et al., 2017; Iqbal et al., 2015)
 
−
*'''Organics'''. Biochar significantly retains polynuclear aromatic hydrocrabons in stormwater runoff (Reddy et al., 2014;  Domingues et al., 2017; Ulrich et al., 2017; Iqbal et al., 2015)
 
−
*'''Bacteria and viruses'''. Biochar effects on bacteria and virus retention are a function of the particle size of the biochar. Fine-grained biochars enhance removal of bacteria in stormwater runoff through straining of microorganisms (Reddy et al., 2014; Sasidharan et al., 2016; Yang et al., 2019).
 
−
*'''Dissolved organic carbon'''. Biochar shows limited retention of dissolved carbon in stormwater runoff (Iqbal et al., 2015).
 
−
*'''Greenhouse gas emissions'''. Biochar effectively sequesters carbon and reduces loss of greenhouse gases when incorporated into soil or media, particularly soil with high organic matter content (Zhaoa et al., 2013; Mohanty et al., 2018; 37. Agyarko-Mintah et al., 2017).
 
−
 
−
===Effect of biochar on soil physical and hydraulic properties===
 
−
Because of a large surface area and internal porosity, biochar can affect soil physical properties (Mohanty et al., 2018; Herrera Environmental Consultants, 2015; Iqbal et al., 2015; Imhoff, 2019; Jien and Wang, 2013). These effects are most pronounced in soils with low organic matter concentration.
 
−
 
−
*'''Porosity and surface area'''. Biochar significantly increases the porosity of most soils.
 
−
*'''Water holding capcity'''. Biochar significantly increases the water holding capacity of soil.
 
−
*'''Hydraulic conductivity'''. Biochar increases the hydraulic conductivity of fine- and medium-grained soils and may decrease the hydraulic conductivity of coarse-grained soils.
 
−
*'''Structure'''. Biochar enhances aggregation in soils, thus enhancing soil structure and potentially increasing soil macroporosity.
 
−
 
−
===Effects of biochar on soil fertility, plant growth, and microbial function===
 
−
<div style="float:right">
 
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<table class="infobox" style="border:3px; border-style:solid; border-color:#FF0000; text-align: right; width: 300px; font-size: 100%">
 
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<tr>
 
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<td>'''Effects of biochar on soil fertility, plant growth, and microbial function are affected by several factors, including feedstock, production method, soil, application rate, and biochar age. Biochar has few negative effects on fertility, plant growth and microbial function and in many cases has the potential to greatly improve soil physical, chemical and biological conditions.'''
 
−
</td>
 
−
</tr>
 
−
</table>
 
−
</div>
 
−
 
−
DeLuca et al. (2015) provide an extensive discussion of biochar effects on nutrient cycling, fertility, and microbial function in soil. Their paper is based on an extensive review of the literature at the time of their publication. The following discussion is primarily based on information contained in this document. A list of suggested articles is provided at the end of this section.
 
−
 
−
Biochars derived from nutrient rich sources such as manure and sludge may directly provide nutrients. Most biochars, however, have limited direct contribution to the nutrient pool with the exception of potassium and ammonium. Biochar may accelerate nutrient cycling over long time scales by serving as a short-term source of highly available nutrients, which become
 
−
incorporated into living biomass and labile soil organic pools. Thus biochar, while typically providing modest inputs of nutrients, enhances the bioavailability of nutrients in soil.
 
−
 
−
Because biochar typically enhances soil physical properties, including increasing water holding capacity, improving gas exchange, increasing surface area and availability of microsites for microbes, and in some cases increasing cation exchange capacity, biochar enhances microbial activity in soil. In addition, carbon in biochar provides a sorptive surface that can retain nutrients and thus minimize leaching and volatilization of nutrients.
 
−
 
−
Several studies suggest biochar amendments in soil result in increased microbial biomass, while other studies show no effect. Mixed results have also been observed for the effects of biochar on microbial community composition.
 
−
 
−
Specific conclusions from the DeLuca et al. (2015) paper include the following.
 
−
*Biochar increases nitrogen mineralization is soils with low mineralization potential (e.g. forest soils). Wood-based biochars appear to have the greatest effect on mineralization.
 
−
*Aged biochar shows greater accumulation of inorganic nitrogen, suggesting reduced nitrogen availability and cycling over time. Additions of fresh biochar are recommended if continued enhanced nutrient cycling is desired.
 
−
*Low-temperature biochars have greater nitrogen immobilization due to more bioavailable carbon, but immobilization to these biochars is likely to be short-term.
 
−
*Biochar effects on nitrogen fixation are mixed, but studies of compost-biochar mixes show a decrease in nitrogen fixation while wood-based biochars show increased fixation.
 
−
*Phosphorus in wood-based biochars is largely immediately soluble and readily released to soil, where it becomes available to plants. However, the overall phosphorus concentration in wood-based biochars is much lower than in manure- or sludge-based biochars.
 
−
*Application of biochar at varying rates result in an increase in available soil phosphorus, but there is little evidence this translates into increased plant uptake. This may be due to presence of abundant sites for adsorption in fresh biochars. Phosphorus decreases over time as biochar ages.
 
−
*Laboratory studies have shown that biochar addition induces an increase in phosphatase activity which would increase the release of P from soil organic matter and organic residues.
 
−
*Biochar effects on phosphorus are likely to be greatest in acidic soils, where addition of biochar raises pH and increases the potential adsorption to alkaline metals (calcium, potassium, magnesium).
 
−
*Biochar effects on sulfur are uncertain, but are likely to be similar to those for phosphorus. Any enhanced adsorption or mobilization, particularly in aged biochar, will most likely be attributable to enhanced water holding capacity and surface area.
 
−
 
−
'''Recommended reading'''
 
−
*Anderson, C. R., Condron, L. M., Clough, T. J., Fiers, M., Stewart, A., Hill, R. A. and Sherlock, R. R. (2011) ‘Biochar induced soil microbial community change: Implications for biogeochemical cycling of carbon, nitrogen and phosphorus’,  Pedobiologia, vol 54, pp309–320.
 
−
*Borchard, N., Wolf, A., Laabs, V., Aeckersberg, R., Scherer, H. W., Moeller, A. and Amelung, W. (2012a) ‘Physical activation of biochar and its meaning for soil fertility and nutrient leaching – a greenhouse experiment’, Soil Use and Management, vol 28, pp177–184
 
−
*Chan, K. Y. and Xu, Z. (2009) ‘Biochar: nutrient properties and their enhancement’, in J. Lehmann and S. Joseph (eds) Biochar for Environmental Management, Earthscan, London, pp 67–84
 
−
*Clough, T. J. and Condron, L. M. (2010) ‘Biochar and the nitrogen cycle: introduction’, Journal of Environmental Quality, vol 39, pp1218–1223
 
−
*Crutchfield, E. F., Merhaut, D. J., Mcgiffen, M. E. and Allen, E. B. (2010) ‘Effects of biochar on nutrient leaching and plant growth’, Hortscience, vol 45, S163–S163.
 
−
*Jeffery, S., Verheijen, F. G. A., Van Der Velde, M. and Bastos, A. C. (2011) ‘A quantitative review of the effects of biochar application to soils on crop productivity using meta-analysis’, Agriculture Ecosystems and Environment, vol 144, pp175–187
 
−
*Jones, D. L., Rousk, J., Edwards-Jones, G., DeLuca, T. H. and Murphy, D. V. (2012) ‘Biochar-mediated changes in soil quality and plant growth in a three year field trial’, Soil Biology and Biochemistry, vol 45, pp113–124
 
−
*Joseph, S. D., Downie, A., Munroe, P., Crosky, A. and Lehmann, J. (2007) ‘Biochar for carbon sequesteration, reduction of greenhouse gas emissions and enhancement of soil fertility; a review of the materials science’ Proceedings from  Australian Combustion Symposium, University of Sydney, Australia, pp1–4
 
−
*Laird, D., Fleming, P., Wang, B., Horton, R. and Karlen, D. (2010) ‘Biochar impact on nutrient leaching from a Midwestern agricultural soil’, Geoderma, vol 158, pp436–442
 
−
*Lehmann, J., Rillig, M. C., Thies, J., Masiello, C. A., Hockaday, W. C. and Crowley, D. (2011) ‘Biochar effects of soil biota – A review’, Soil Biology and Biochemistry, vol 43, pp1812–1836
 
−
*Nelson, N. O., Agudelo, S. C., Yuan, W. and Gan, J. (2011) ‘Nitrogen and phosphorus availability in biochar-amended soils’, Soil Science, vol 176, pp218–226
 
−
*Pietikäinen, J., Kiikkila, O. and Fritze, H. (2000) ‘Charcoal as a habitat for microbes and its effect on the microbial community of the underlying humus’, Oikos, vol 89, pp231–242
 
−
*Quilliam, R. S., Marsden, K. A., Gertler, C., Rousk, J., DeLuca, T. H. and Jones, D. L. (2012) ‘Nutrient dynamics, microbial growth and weed emergence in biochar amended soil are influenced by time since application and reapplication rate’,  Agriculture, Ecosystems, and Environment, vol 158, pp192–199
 
−
*Schultz, H. and Glaser, B. (2012) ‘Effects of biochar compared to organic and inorganic fertilizers on soil quality and plant growth in a greenhouse experiment’, Journal of Soil Science and Plant Nutrition, vol 175, pp410–422
 
−
*Yoo, G. and Kang, H. (2010) ‘Effects of biochar addition on greenhouse gas emissions and microbial responses in a short-term laboratory experiment’, Journal of Environmental Quality, vol 41, pp1193–1202
 
−
 
−
==Standards, classification, testing, and distributors==
 
−
Because of the large number of potential feedstocks, production conditions (primarily temperature), and applications for biochar, biochar classification is an active area of research. The information in this section largely comes from the [https://biochar-international.org/ International Biochar Initiative], but some additinal references include the following.
 
−
 
−
*Arbestain et al. (2015): A biochar classification system and associated test methods
 
−
*Klassen (2017): Biochar characterization and a method for estimating biochar quality from proximate analysis results
 
−
*Leng et al. (2019): Biochar stability assessment methods: A review
 
−
*[https://biochar-us.org/go-deeper United States Biochar Initiative]
 
−
*Budai et al. (2013): Biochar Carbon Stability Test Method: An Assessment of methods to determine biochar carbon stability
 
−
 
−
===Biochar standards===
 
−
The Internation Biochar Initiative (IBI) developed Standardized Product Definition and Product Testing Guidelines for Biochar That Is Used in Soil, also referred to The Biochar Standards. These standards provide guidelines and is not a formal set of industry specifications. The goal of The Biochar Standards is to "universally and consistently define what biochar is, and to confirm that a product intended for sale or use as biochar possesses the necessary characteristics for safe use. The IBI Biochar Standards also provide common reporting requirements for biochar that will aid researchers in their ongoing efforts to link specific functions of biochar to its beneficial soil and crop impacts." The IBI also provides a certification program. Information on the standards and certification are found on [https://biochar-international.org/characterizationstandard/ International Biochar Institute's website] or at the [https://www.biochar-international.org/wp-content/uploads/2018/04/IBI_Biochar_Standards_V2.1_Final.pdf IBI's Standardized Product Definition and Product Testing Guidelines for Biochar That Is Used in Soil].
 
−
 
−
The IBI also provides [https://biochar-international.org/biochar-classification-tool/ a biochar classification tool]. Currently, four biochar properties are classified:
 
−
*Carbon storage value
 
−
*Fertilizer value (P, K, S, and Mg only)
 
−
*Liming value
 
−
*Particle size distribution
 
−
 
−
===Distributors===
 
−
{{alert|The Minnesota Pollution Control Agency does not endorse specific distributors of biochar or biochar products|alert-warning}}
 
−
 
−
A list of biochar distributors is provided on the [https://biochar-us.org/manufacturers-retailers United States Biochar Initiative website (USBI)]. Note the USBI neither provides endorsements nor accepts liability for any particular product or technology listed.
 
−
 
−
===Test methods===
 
−
There is no universally accepted standard for biochar testing. The Internation Biochar Initiative (IBI) developed [https://biochar-international.org/wp-content/uploads/2019/11/IBI_Biochar_Standards_V2.1_Final1.pdf Standardized Product Definition and Product Testing Guidelines for Biochar That Is Used in Soil]. The goals of this document are to provide "stakeholders and 5 commercial entities with standards to identify certain qualities and characteristics of biochar materials according to relevant, reliable, and measurable characteristics." The document provides information and test parameters and test nethods for three categories.
 
−
*Test Category A – Basic Utility Properties (required)
 
−
*Test Category B – Toxicant Assessment (required)
 
−
*Test Category C – Advanced Analysis and Soil Enhancement Properties
 
−
 
−
The IBI document also provides information on sampling procedures, laboratory standards, timing and frequency of testing, feedstcok and production parameters, frequency of testing, reporting, and additional information for specific types of biochar. The document also [https://biochar-international.org/wp-content/uploads/2019/11/IBI_Biochar_Standards_V2.1_Final1.pdf provides a discussion of H:C ratios], which are used to indicate the stability of a particular biochar.
 
−
 
−
==Effects of aging==
 
−
Biochar undergoes transformations in soil after application, primarily through oxidation processes, typically mediated by microbes. Several researchers have studied effects of aging on biochar properties. Although researchers observe similar changes in the chemical and physical structure of biochar with aging, observed effects vary. It is therefore difficult to draw general conclusions about likely changes in the effects of biochar aging on fate of pollutants and soil hydraulic properties.
 
−
 
−
Below is a summary of some research findings.
 
−
*Mia et al. (2019) observed an increase in carboxylic and phenolic groups, a reduction of oxonium groups and the transformation of pyridine to pyridone with oxidation. This led to increased adsorption of ammonium and reduced adsorption of phosphate. Addition of biochar derived organic matter improved phosphate retention.
 
−
*Paetsch et al. (2018) studied effects of fresh and aged biochar on water availability and microbial parameters of a grassland soil. They observed improved water retention and microbial function with aged biochar. This was attributed to increased soil mineralization in soils with aged biochar.
 
−
*Paetsch et al. (2018) observed increased C:N ratios as biochar aged.
 
−
*Dong et al. (2017) observed increased specific surface area, increased carbon content, smaller average pore size, but no change in chemical structure of aged biochar versus fresh biochar.
 
−
*Quan et al. (2020) and Spokas (2013) observed biologically-mediated changes in aged biochar. Mineralization resulted in decreased carbon content in aged biochar.
 
−
*Hale et al. (2012) determined that aged biochar retained its ability to adsorb PAHs.
 
−
*Cao et al. found that aged biochar had decreased carbon and nitrogen contents; reduced pH values, reduced porosity and specific surface area, and increased oxygen-containing functional groups on the surface. In general, the surface characteristics of the aged biochar varied with soil type.
 
−
 
−
==Storage, handling, and field application==
 
−
The following guidelines for field application of biochar are presented by Major (2010).
 
−
*Biochar dust particles can form explosive mixtures with air in confined spaces, and there is a danger of spontaneous heating and ignition when biochar is tightly packed. This occurs because fresh biochar quickly sorbs oxygen and moisture, and these sorption processes are exothermic, thus potentially leading to high temperature and ignition of the material.
 
−
*Volatile compounds present in certain biochar materials may also represent a fire hazard, but the amount of such compounds found in biochar can be managed by managing the pyrolysis temperature and heating rate. Certain chemicals can be added to biochar to decrease its flammability (e.g. boric acid, ferrous sulfate). The best way to prevent fire is to store and transport biochar in an atmosphere which excludes oxygen. Formulated biochar products such as mixtures with composts, manures, or the production of biochar-mineral complexes will potentially yield products which are much less flammable.
 
−
*For fine-grained biochars, wind losses can be significant (up to 30% loss has been reported). Biochar can be moistened, although this will add to the weight of the material and increase transportation costs. If wind loss is a concern, apply biochar when winds are mild and/or during a light rain. Pelleted biochars or mixing with other materials may reduce wind loss.
 
−
*To avoid water erosion, incorporate biochar into the soil.
 
−
*Application rates vary depending on the biochar and the intended use of the biochar.
 
−
*Biochar is relatively stable and recalcitrant. In some cases, biochar may improve soil conditions with time. Consequently, biochar application frequency is likely to be on the order of years.
 
−
*Biochar can be readily mixed with other materials, such as compost.
 
−
*The depth of biochar application varies with the intended purpose.
 
−
**For fertility applications, locate biochar near the soil surface in the active rooting zone.
 
−
**For moisture management, locate biochar throughout the root zone.
 
−
**For carbon sequestration, locate biochar deeper in the soil profile to reduce the likelihood of microbial mineralization.
 
−
*For stormwater applications, biochar can be broadcast and then incorporated into the soil. If fertility is the primary objective, banding may be utilized.
 
−
*For turf applications, biochar can be mixed with soil (sand and topsoil) and other amendments such as compost.
 
−
*Application rates depend on the intended use of a biochar. Field testing is recommended prior to application. Typical rates reported in the literature are 5-50 tonnes of biochar per hectare.
 
−
 
−
==Sustainability==
 
−
Because biochar is produced from biomass, including wastes, it is sustainable from an availability or supply standpoint. Sustainable biochar production, however, is less certain based on current economic constraints. Biochar has several potential markets and exploiting these markets is necessary for biochar production to be sustainable. Examples of specific markets include stormwater media, soil health and fertility, and carbon sequestration [Biogreen http://www.biogreen-energy.com/biochar-production/] (accessed December 10, 2019). Sustainable biochar production must also meet certain environmental and economic criteria, includign the following.
 
−
*Biochar systems should be, at a minimum, carbon and energy neutral.
 
−
*Biochar systems should prioritize the use of biomass residuals for biochar production.
 
−
*Biochar systems should be safe, clean, economical, efficient, and meet or exceed environmental standards and regulatory requirements of the regions where they are deployed.
 
−
*Biochar systems should promote or enhance ecological conditions for biodiversity at the local and landscape level.
 
−
*Biochar systems should not pollute or degrade water resources.
 
−
*Biochar systems should not jeopardize food security by displacing or degrading land grown for food; and should seek to complement existing local agro-ecological practices.
 
−
 
−
For more information, see the [https://biochar-international.org/sustainability-climate-change/ International Biochar Initiative discussion] on sustainable biochar production. For a discussion of biochar sustainability, see [https://www.researchgate.net/publication/275770511_Biochar_Sustainability_and_Certification  sustainability and Certification] (Vereijen et al., 2015).
 
−
 
−
==References==
 
−
 
−
*[https://biochar.international/guides/properties-fresh-aged-biochar/ THE PROPERTIES OF FRESH & AGED BIOCHAR]
 
−
*[https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=3291&context=etd  characterization and engineering]
 
−
 
−
*Agyarko-Mintah E, Cowie A, Singh BP, Joseph S, Van Zwieten L, Cowie A, Harden S, Smillie R.. 2017. Biochar increases nitrogen retention and lowers greenhouse gas emissions when added to composting poultry litter. Waste Manag. 61:138-149. doi: 10.1016/j.wasman.2016.11.027. Epub 2016 Dec 8.
 
−
*Budai; A. R. Zimmerman; A.L. Cowie; J.B.W. Webber; B.P. Singh; B. Glaser; C. A. Masiello; D. Andersson; F. Shields; J. Lehmann; M. Camps Arbestain; M. Williams; S. Sohi; S. Joseph. 2013. Biochar Carbon Stability Test Method: An Assessment of methods to determine biochar carbon stability. Accessed December 12, 2019.
 
−
*Cao, T., Wenfu Chen, Tiexin Yang, Tianyi He, Zunqi Liu, Jun Meng. 2017. Surface Characterization of Aged Biochar Incubated in Different Types of Soil. BioResources. 12:3: 6366-6377
 
−
*Conz, R., T. Abbruzzini, C.A. de Andrade, D.M.B.P. Milori. 2017. Effect of Pyrolysis Temperature and Feedstock Type on Agricultural Properties and Stability of Biochars. Agricultural Sciences 8:9:914-933.
 
−
*DeLuca, T.H., M.D. MacKenzie, D.L. Jones. 2015. Biochar effects on soil nutrient transformations.
 
−
*Ding, Y., Yu-Xue Liu, Wei-Xiang Wu, De-Zhi Shi, Min Yang, and Zhe-Ke Zhong. 2010. Evaluation of Biochar Effects on Nitrogen Retention and Leaching in Multi-Layered Soil Columns. Water, Air, & Soil Pollution. Volume 213, Issue 1–4, pp 47–55.
 
−
*Domingues, R.R., Paulo F. Trugilho, Carlos A. Silva, Isabel Cristina N. A. de Melo, Leoà nidas C. A. Melo, Zuy M. Magriotis, Miguel A. SaÂnchez-Monedero. 2017. Properties of biochar derived from wood and high-nutrient biomasses with the aim of agronomic and environmental benefits. PLOS ONE
 
−
*Flesch, F., Pia Berger, Daniel Robles-Vargas , Gustavo Emilio Santos-Medrano, and Roberto Rico-Martínez. 2019. Characterization and Determination of the Toxicological Risk of Biochar Using Invertebrate Toxicity Tests in the State of Aguascalientes,México. Appl. Sci. 2019, 9, 1706; doi:10.3390/app9081706.
 
−
*Gai X, Wang H, Liu J, Zhai L, Liu S, et al. (2014) Effects of Feedstock and Pyrolysis Temperature on Biochar Adsorption of Ammonium and Nitrate. PLoS ONE 9(12). 19 pages. doi:10. 1371/journal.pone.0113888.
 
−
*Hale, S.E. Kelly Hanley, Johannes Lehmann, Andrew R. Zimmerman, and Gerard Cornelissen. 2012. Effects of Chemical, Biological, and Physical Aging As Well As Soil Addition on the Sorption of Pyrene to Activated Carbon and Biochar. Environ Sci Tech.
 
−
*Han, Y., Byoungkoo Choi, and Xiangwei Chen. 2018. Adsorption and Desorption of Phosphorus in Biochar-Amended Black Soil as Affected by Freeze-Thaw Cycles in Northeast China.
 
−
*Hardy, B., Steven Sleutel, Joseph E. Dufey, and Jean-Thomas Cornelis. 2019. The Long-Term Effect of Biochar on Soil Microbial Abundance, Activity and Community Structure Is Overwritten by Land Management. Frontiers Environ. Sci. 110:7:1-14. DOI: 10.3389/fenvs.2019.00110.
 
−
*Hoffman-Krull, K.H. 2019. [https://rodaleinstitute.org/blog/whats-biochar-how-to-stabilize-carbon-in-your-soil/ WHAT’S BIOCHAR? HOW TO STABILIZE CARBON IN YOUR SOIL]. Rodale Institute.
 
−
*Internation Biochar Initiative. Biochar Feedstocks. Accessed December 12, 2019.
 
−
*Iqbal, H., Manuel Garcia-Perez, Markus Flury. 2015. Effect of biochar on leaching of organic carbon, nitrogen, and phosphorus from compost in bioretention systems Science of the Total Environment 521–522 (2015) 37–45
 
−
*Jahromi, N.B., and A. Fulcher. What is Biochar and How Different Biochars Can Improve Your Crops. University of Tennessee Extension. Publication W829. Accessed 12/12/2019.
 
−
*Jien, Shih-Hao, and Chien-Sheng Wang. 2013. Effects of biochar on soil properties and erosion potential in a highly weathered soil. Catena. 110:225-233
 
−
*Jindo, K., H. Mizumoto3, Y. Sawada, M. A. Sanchez-Monedero1, and T. Sonoki. 2014. Physical and chemical characterization of biochars derived from different agricultural residues. Biogeosciences, 11, 6613–6621.
 
−
*Kasak, K., Jaak Truu, Ivika Ostonen, Jürgen Sarjas, Kristjan Oopkaup, Päärn Paiste, Margit Kõiv-Vainik, Ülo Mander, Marika Truu. 2018. Biochar enhances plant growth and nutrient removal in horizontal subsurface flow constructed wetlands Science of the Total Environment 639:67–74
 
−
*Klasson, T.K. 2017. Biochar characterization and a method for estimating biochar quality from proximate analysis results. Biomass and Bioenergy. 96:50-58.
 
−
*Laird, D., Pierce Flemming, Baiqun Wang, Robert Horton, Douglas Karlen. 2010. Biochar impact on nutrient leaching from a Midwestern agricultural soil. Agronomy Publications. Iowa State University. 9 p.
 
−
*Lyu H, He Y, Tang J, Hecker M, Liu Q, Jones PD, Codling G, Giesy JP. 2016. Effect of pyrolysis temperature on potential toxicity of biochar if applied to the environment. Environ Pollut. 218:1-7. doi: 10.1016/j.envpol.2016.08.014.
 
−
*Major, J. 2010. [https://www.biochar-international.org/wp-content/uploads/2018/04/IBI_Biochar_Application.pdf Guidelines on Practical Aspects of Biochar Application to Field Soil in Various Soil Management Systems].
 
−
*Mensah, A.K., and Kwame Agyei Frimpong. 2018. Biochar and/or Compost Applications Improve Soil Properties, Growth, and Yield of Maize Grown in Acidic Rainforest and Coastal Savannah Soils in Ghana. International Journal of Agronomy. Volume 2018, 8 pages. https://doi.org/10.1155/2018/6837404
 
−
*Mohanty, S.K., Renan Valenca, Alexander W. Berger, Iris K.M. Yu, Xinni Xiong, Trenton M. Saunders, Daniel C.W. Tsang. 2018. Plenty of room for carbon on the ground: Potential applications of biochar for stormwater treatment Science of the Total Environment, 625: 1644-1658.
 
−
*Mumme J, Getz J, Prasad M, Lüder U, Kern J, Mašek O, Buss W. 2018. Toxicity screening of biochar-mineral composites using germination tests. Chemosphere. 207:91-100. doi:10.1016/j.chemosphere.2018.05.042.
 
−
*Nabiul Afrooz, A.R.M., Ana K. Pitol, Dianna Kitt, and  Alexandria B. Boehm. 2018. Role of microbial cell properties on bacterial pathogen and coliphage removal in biochar-modified stormwater biofilters. Environ Sci: Water Res and Tech. 12:
 
−
*Nguyen, N.T. 2015. Adsorption Of Phosphorus From Wastewater Onto Biochar: Batch And Fixed-bed Column Studies
 
−
*Oleszczuk, P., Izabela Jo´sko, Marcin Ku´smierz. 2013. Biochar properties regarding to contaminants content and ecotoxicological assessment. Journal of Hazardous Materials 260 (2013) 375– 382.
 
−
*Quan G, Fan Q, Zimmerman AR, Sun J, Cui L, Wang H, Gao B, Yan J. 2020. Effects of laboratory biotic aging on the characteristics of biochar and its water-soluble organic products. J Hazard Mater. 2020 Jan 15;382:121071. doi: 10.1016/j.jhazmat.2019.121071
 
−
*Rawat, J., J. Saxena, and P. Sanwal. 2018. Biochar: A Sustainable Approach for Improving Plant Growth and Soil Properties. In: Biochar - An Imperative Amendment for Soil and the Environment. DOI: 10.5772/intechopen.82151
 
−
*Reddy, K.R., Tao Xie, and Sara Dastgheibi. 2014. Evaluation of Biochar as a Potential Filter Media for the Removal of Mixed Contaminants from Urban Storm Water Runoff. Journal Environ Eng. 140:12. https://doi.org/10.1061/(ASCE)EE.1943-7870.0000872
 
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*Shamim Mia, Feike A. Dijkstra, and Balwant Singh. 2017.  Aging Induced Changes in Biochar’s Functionality and Adsorption Behavior for Phosphate and Ammonium. Environ. Sci. Technol. 51:8359−8367. DOI: 10.1021/acs.est.7b00647
 
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*Soinne, H., Jarkko Hovi, PriitTammeorg, EilaTurtola. 2014. Effect of biochar on phosphorus sorption and clay soil aggregate stability. Geoderma. Volumes 219–220, May 2014, Pages 162-167.
 
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*Spears, S. 2018. [https://regenerationinternational.org/2018/05/16/what-is-biochar/ What is Biochar?] Regeneration International.
 
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*Spokas, K.A. 2013. Impact of biochar field aging on laboratory greenhouse gas production potentials. GCB Bioenergy (2013) 5, 165–176, doi: 10.1111/gcbb.12005
 
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*Ulrich, B.A., Megan Loehnert  and  Christopher P. Higgins. 2017. Improved contaminant removal in vegetated stormwater biofilters amended with biochar Environmental Science: Water Research & Technology. 4:
 
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*Wang, K., Na Peng, Guining Lu, Zhi Dang, 2018. Effects of Pyrolysis Temperature and Holding Time on Physicochemical Properties of Swine-Manure-Derived Biochar. Waste and Biomass Valorization. 1-12 DOI: 10.1007/s12649-018-0435-2
 
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*Yang, F., Yue Zhou, Weiming Liu, Wenzhu Tang, Jun Meng, Wenfu Chen, and Xianzhen Li. 2019. Article Strain-Specific Effects of Biochar and Its Water-Soluble Compounds on Bacterial Growth. Appl. Sci. 9(16), 3209; https://doi.org/10.3390/app9163209.
 
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*Yao, Y., Bin Gao, Mandu Inyang, Andrew R. Zimmerman, Xinde Cao, Pratap Pullammanappallil, Liuyan Yang. 2011 Biochar derived from anaerobically digested sugar beet tailings:Characterization and phosphate removal potential. Bioresource Technology. 102:6273-6278
 
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*Yaoa, Y., Bin Gaoa, Mandu Inyanga, Andrew R. Zimmermanb, Xinde Caoc, Pratap Pullammanappallila, Liuyan Yangd. 2011. Removal of phosphate from aqueous solution by biochar derived from anaerobically digested sugar beet tailings. Journal of Hazardous Materials 190:501–507
 
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*Yuan-Ying Wang, Xiang-Rong Jing, Ling-Li Li, Wu-Jun Liu, Zhong-Hua Tong, Hong Jiang. 2017. Biotoxicity Evaluations of Three Typical Biochars Using a Simulated System of Fast Pyrolytic Biochar Extracts on Organisms of Three Kingdoms. ACS Sustainable Chem. Eng. 2017, 5, 1, 481-488. https://doi.org/10.1021/acssuschemeng.6b01859
 
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*Zhang, M., Muhammad Riaz, Lin Zhang, Zeinab El-desouki, and Cuncang Jiang. Biochar Induces Changes to Basic Soil Properties and Bacterial Communities of Different Soils to Varying Degrees at 25 mm Rainfall: More Effective on Acidic Soils. 2019. Frontiers Microbio. 12:10:1321. doi: 10.3389/fmicb.2019.01321
 
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*Zhao, J.J. Xin-Jie Shen, Xavier Domene, Josep-Maria Alcañiz, Xing Liao and Cristina Palet. 2019. Comparison of biochars derived from different types of feedstock and their potential for heavy metal removal in multiple-metal solutions. Scientific Reports 9. Article 9869.
 
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*Zhao, Shi-Xiang, Na Ta and Xu-Dong Wang  2017. Effect of Temperature on the Structural and Physicochemical Properties of Biochar with Apple Tree Branches as Feedstock Material Energies, 10:1293; doi:10.3390/en10091293
 
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*Zhaoa, L., Xinde Caoa, Ondˇrej Maˇsekb, Andrew Zimmerman. 2013. Heterogeneity of biochar properties as a function of feedstock sources and production temperatures. Journal of Hazardous Materials 256– 257:1– 9
 
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*Zheng, H., Zhenyu Wang, Xia Deng, Stephen Herbert, Baoshan Xing. 2013. Impacts of adding biochar on nitrogen retention and bioavailability in agricultural soil. Geoderma, Volume 206:32-39
 
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<th><center>Quick Guide for pretreatment sizing of filter strips</center></th>
 
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'''ENSURE YOUR UNITS ARE CONSISTENT AND CORRECT'''
 
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*Determine, ''v''<sub>''S''</sub>, the settling velocity for the particle size targeted (recommend 80 microns for particle size. Determine v<sub>s</sub> from table on this page)
 
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*Determine ''FR'', the target percent removal (recommend 50-70%)
 
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*Determine ''A'', the area of directly connected impervious draining to the pretreatment practice
 
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*Determine ''I'', the peak rain intensity (0.5 in/hr for a 1-inch event, Type 2 distribution)
 
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*Calculate the area of the filter strip from LW = - ((c * I * A) / (v<sub>S</sub>) * ln(1 - FR)) where c = 0.7 for small storms
 
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*Determine the length (L) and the width (W) from the above computation
 
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[[Stormwater and soil, engineered (bioretention) media, and media amendments]]
 
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[[File:Bioretention media.png|300 px|thumb|alt=image bioretention|<font size=3>Engineered media in a bioretention practice. Image from [https://www.flickr.com/photos/mpcaphotos/albums/72157660843839122 MPCA's Flickr website.]</font size>]]
 
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[[File:Compost image.png|300px|thumb|alt=compost image|<font size=3>Compost is an important component of most engineered media mixes. It is also commonly used as an amendment to improve soil properties, such as infiltration rate, fertility, and structure.  Image from [https://www.flickr.com/photos/mpcaphotos/albums/72157647386550552 MPCA's Flickr website.]</font size>]]
 
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{{alert|Engineered media is manufactured from soil (sand, silt, clay) and other components (e.g. compost, iron, etc.), in specific proportions, for a specific application (e.g. green roof, bioretention, tree box). Because engineered media are widely used in [[Bioretention|bioretention]] practices, the term "bioretention media" is widely used. We prefer the term "engineered media" as it more accurately describes the applicability of these media.|alert-info}}
 
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Soil and engineered media, often referred to as bioretention media, are fundamental design characteristics of most post-construction stormwater practices. In some applications, soil or media amendments are utilized to improve soil conditions or enhance treatment effectiveness of a BMP.
 
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This page provides links to pages that address topics related to soil, engineered media, and soil/media amendments.
 
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*Media
 
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**[[Overview of engineered (bioretention) media]]
 
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**[[Engineered (bioretention) media materials specifications]]
 
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**[[Stormwater engineered (bioretention) media mixes]]
 
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**[[Engineered (bioretention) media applications for stormwater BMPs]]
 
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**[[Phosphorus leaching, export, and retention in engineered (bioretention) stormwater media]]
 
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**[[Review and summary of literature pertaining to engineered (bioretention) media]]
 
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**[[Engineered (bioretention) media selection tool]]
 
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*Amendments
 
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**[[Compost and stormwater management]]
 
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**[[Stormwater media amendments materials specifications]]
 
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**[https://stormwater.pca.state.mn.us/index.php?title=Soil_amendments_to_enhance_phosphorus_sorption Soil amendments to enhance phosphorus sorption]
 
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*Soil
 
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**[[Understanding and interpreting soils and soil boring reports for infiltration BMPs]]
 
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**[[Determining soil infiltration rates]]
 
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**[[Design guidelines for soil characteristics - tree trenches and tree boxes]]
 
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**[[Guidance for amending soils with rapid or high infiltration rates]]
 
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**[https://stormwater.pca.state.mn.us/index.php?title=Category:Soil_properties Soil properties]
 
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*Vegetation
 
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**[[Minnesota plant lists]]
 
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**[https://stormwater.pca.state.mn.us/index.php?title=Plants_for_swales Plants for swales]
 
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**[https://stormwater.pca.state.mn.us/index.php?title=Plant_lists_for_trees Plant lists for trees]
 
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*Links
 
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*[[Photo gallery for Stormwater and soil, engineered (bioretention) media, and media amendments]]
 
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*Interesting websites
 
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Revision as of 16:44, 7 June 2021

Warning: This page is an edit and testing page use by the wiki authors. It is not a content page for the Manual. Information on this page may not be accurate and should not be used as guidance in managing stormwater.

Operation and Maintenance of Bioretention and Other Stormwater Infiltration Practices

Overview of Typical O&M Issues Bioretention practices and other stormwater infiltration practices like rain gardens and infiltration trenches are vegetated landscape practices that capture, filter, and infiltrate stormwater runoff. In addition, these practices can provide ecosystem services such as nutrient cycling and storage, carbon sequestration, reduction in heat island effect, climate adaptation, and habitat for bees, butterflies, and other insects and small animals that pollinate. Bioretention and other infiltration practices may be subject to higher public visibility, greater trash loads, pedestrian traffic, vandalism, and vehicular loads, particularly in urban areas.

These practices require dedicated and regular maintenance to ensure proper and long-lasting operation and ecosystem benefits. The most frequently cited O&M concerns for infiltration practices include:

  • Permanent standing water or flooding due to clogging caused by organic matter, fine silts, hydrocarbons, and algal matter. Clogging can occur at the surface, or in the inlet, outlet, or underdrain pipes.
  • Runoff bypasses the practice due to incorrect grading and slopes, or because the inlet is blocked.
  • Accumulation of trash and debris within the infiltration practice.
  • Insufficient/inadequate vegetation or overcrowded vegetation .
  • Inadequate pollutant removal due to improper soil media selection.

The sections below describe best practices to prevent or minimize these common problems.

Design Phase O&M Considerations

Designers should design bioretention and infiltration practices in ways that prevent or minimize O&M issues. Examples include:

  • Limiting the contributing drainage area and sizing the practice in accordance to its contributing drainage area to prevent flooding issues.
  • Providing pre-treatment and trash racks to prevent clogging or trash accumulation.
  • Providing a vegetation design plan, emphasizing native plantings (see Plants for Stormwater Design) to enhance pollinator and wildlife habitat, improve infiltration and evapotranspiration, reduce urban heat island effect, provide optimized carbon sequestration, and provide climate adaptation.
  • Specifying the optimized soil media composition and depth to effectively trap or sequester nutrients (phosphorus in particular), and that can also support the desired vegetation.
  • Providing educational signage to increase public awareness.
  • Installing measures like low fencing to prevent damage from pedestrian foot traffic .

Designers should also recognize the need to perform frequent landscaping maintenance to remove trash, check for clogging, and maintain vigorous and healthy vegetation. Designers can incorporate design solutions to facilitate maintenance activities. Examples include:

  • Incorporating multiple and easy site access points
  • Installing observation wells
  • Providing recommendations of vegetation appropriate to the location

The designer should also provide a site-specific O&M plan that includes the following:

  • Construction inspection schedule and checklists
  • Post-construction routine maintenance schedule and checklists
  • Operating instructions for the practice (if applicable)

Example O&M plans are provided further down.

For more design information and criteria for individual infiltration practices, see the “design criteria for bioretention” or “design criteria for infiltration practices” pages.

Construction Phase O&M Considerations Proper construction methods and sequencing play a significant role in reducing O&M problems. Some key items during the construction phase include:

  1. Before construction begins:
    1. Ensure that the contributing drainage area is fully stabilized with vegetation prior to the beginning of construction. Also make sure that impervious areas in the contributing drainage area are clean. If this is not possible, use barriers or diversions to direct stormwater flows from the contributing drainage area away from the practice.
    2. Install any needed erosion and sediment controls in your construction site and prepare a storm water pollution prevention plan (SWPPP).
    3. Designate a stormwater supervisor to make sure someone is responsible for erosion and sediment control.
    4. Hold a pre-construction meeting with the designer and the installer to review the construction plans and the sequencing of construction.
  2. During construction:
    1. Construct any pre-treatment devices before constructing the main bioretention or infiltration system.
    2. Ensure heavy equipment does not enter the footprint of the practice to avoid compaction of the infiltration medium.
    3. Store any soil or gravel media downstream of the practice footprint to avoid clogging the infiltration medium. If this is not possible, store soil or gravel media in some type of covered or contained structure.
    4. Inspect the practice during construction to ensure that the infiltration practice is built in accordance with the approved design and standards and specifications. This includes verification of the media composition and depths. Use a detailed inspection checklists that include sign-offs by qualified individuals at critical stages of construction, to ensure that the contractor’s interpretation of the plan is acceptable to the professional designer. Example construction phase inspection checklists are provided further down below.
    5. Ensure that the plant and vegetation mix conforms to the vegetation design plan, particularly if the vegetation was selected to provide ecological function (such as pollinator habitat).
  3. After construction:
    1. Verify that the infiltration practice was built in accordance with the approved design and standards and specifications, including the pre-treatment devices as well as the main infiltration practice.
    2. Verify that the contributing drainage area is fully stabilized with vegetation prior to removing any barriers, diversions, or erosion and sediment control measures.
    3. Verify that the practice actually captures and infiltrates runoff. Conduct a full inundation test to inspect the underdrain and outflow function.
    4. Verify that the practice reduces nutrient loads. Collect inflow and outflow storm water samples and have them analyzed for nutrient concentrations.
    5. Use a detailed inspection checklist that includes sign-offs by qualified individuals at the completion of construction, to ensure that the contractor’s interpretation of the plan is acceptable to the professional designer. Example construction phase inspection checklists are provided further down below.

Post-Construction Phase O&M

Effective short and long-term operation of bioretention and infiltration practices requires dedicated and routine maintenance. Proper maintenance will not only increase the expected lifespan of the facility but will improve ecological function, aesthetics, and property value. Important post-construction considerations are provided below.

  • A site-specific Operations and Maintenance Plan should be prepared by the designer prior to putting the stormwater practice into operation. This plan should provide any operating procedures related to the practices. The plan should also provide clear maintenance expectations, activities, and schedules. The O&M plan should also include an example O&M inspection checklist and an example maintenance report. Example O&M plans and inspection checklists are provided further down below.
  • A legally binding and enforceable maintenance agreement should be executed between the practice owner and the local review authority. Example maintenance agreements are provided further down below.
  • Maintenance activities should be careful not to cause compaction or damage to the vegetation. No vehicles or stockpiling should be allowed within the footprint of the practice. Foot traffic should be kept to a minimum.
  • Maintenance activities should apply to all parts of the bioretention or infiltration practices, including the pre-treatment devices, the main bioretention/infiltration area, the vegetation, the media, and any conveyance or discharge pipes.
  • BMP areas generally should not be used as dedicated snow storage areas. Click here for additional snow and salt considerations.






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