Difference between revisions of "Minnesota Stormwater Manual test page 5"
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==Phosphorus quiz== | ==Phosphorus quiz== | ||
| − | #Dissolved phosphorus is about how many times more bioavailable than particulate phosphorus? 1, 5, 20 <p style="color:red;"> 5. Dissolved P is about 90 percent bioavailable, compared to about 20% for particulate P</p> | + | #Dissolved phosphorus is about how many times more bioavailable than particulate phosphorus? 1, 5, 20 <p style="color:red;">5. Dissolved P is about 90 percent bioavailable, compared to about 20% for particulate P</p> |
| − | #Median concentrations of total phosphorus in stormwater are about how many times greater than water quality standards? 1, 3, 10 | + | #Median concentrations of total phosphorus in stormwater are about how many times greater than water quality standards? 1, 3, 10<p style="color:red;">Approximately 3 - 0.30 mg/L compared to 0.10 mg/L, though concentrations and standards vary</p> |
| − | #True or false: Most phosphorus in stormwater runoff is in dissolved forms. | + | #True or false: Most phosphorus in stormwater runoff is in dissolved forms.<p style="color:red;">False - particulate P is about 60 percent of TP across all land uses, with the percent being higher in industrial/transportation settings and lower in residential settings.</p> |
| − | #Which of these is a more important source of dissolved phosphorus: sediment or organic material (e.g. leaves). | + | #Which of these is a more important source of dissolved phosphorus: sediment or organic material (e.g. leaves).<p style="color:red;">Organic material, including plant material and animal waste</p> |
| − | #Street sweeping for phosphorus would be more effective in which of these: downtown Minneapolis, a high canopy area in St. Paul, a new development in Maple Grove | + | #Street sweeping for phosphorus would be more effective in which of these: downtown Minneapolis, a high canopy area in St. Paul, a new development in Maple Grove<p style="color:red;">A high canopy area in St. Paul, due to the importance of organic material as a source of dissolved P</p> |
| − | #Reasons why stormwater ponds export phosphorus include which of the following (select all that apply): turn over too frequently, turn over too infrequently, oxygen exists in the hypolimnion, inadequate maintenance, excess organic material entering the pond, excess canopy cover adjacent to pond prevents mixing | + | #Reasons why stormwater ponds export phosphorus include which of the following (select all that apply): turn over too frequently, turn over too infrequently, oxygen exists in the hypolimnion, inadequate maintenance, excess organic material entering the pond, excess canopy cover adjacent to pond prevents mixing<p style="color:red;">Ponds that turn over infrequently, that are poorly maintained, that have high organic inputs, and that are shaded and therefore not mixed have a greater tendency to export P</p> |
| − | #True or false: Biochar is effective at absorbing phosphorus | + | #True or false: Biochar is effective at absorbing phosphorus<p style="color:red;">False. Biochar does not appear to leach P, but it has not been show to absorb P.</p> |
| − | #At about what % compost will bioretention media begin to leach phosphorus: 5, 10, 20 | + | #At about what % compost will bioretention media begin to leach phosphorus: 5, 10, 20<p style="color:red;">We aren't sure what the cutoff is yet, but research suggests compost concentrations of greater than 5% in bioretention media will leach P.</p> |
| − | #True or false: Infiltration of stormwater runoff is an excellent | + | #True or false: Infiltration of stormwater runoff is an excellent method for reducing phosphorus loading to surface water<p style="color:red;">True. P is attenuated in the unsaturated zone and in groundwater</p> |
| − | #True or false: in residential areas, runoff from surfaces considered to be permeable is an important source of dissolved phosphorus | + | #True or false: in residential areas, runoff from surfaces considered to be permeable is an important source of dissolved phosphorus<p style="color:red;">True. Runoff from frozen soils and overirrigated lawns are considered important sources of dissolved P, though more research is needed to quantify these sources.</p> |
==a== | ==a== | ||
Revision as of 14:54, 19 October 2020
Contents
Phosphorus quiz
- Dissolved phosphorus is about how many times more bioavailable than particulate phosphorus? 1, 5, 20
5. Dissolved P is about 90 percent bioavailable, compared to about 20% for particulate P
- Median concentrations of total phosphorus in stormwater are about how many times greater than water quality standards? 1, 3, 10
Approximately 3 - 0.30 mg/L compared to 0.10 mg/L, though concentrations and standards vary
- True or false: Most phosphorus in stormwater runoff is in dissolved forms.
False - particulate P is about 60 percent of TP across all land uses, with the percent being higher in industrial/transportation settings and lower in residential settings.
- Which of these is a more important source of dissolved phosphorus: sediment or organic material (e.g. leaves).
Organic material, including plant material and animal waste
- Street sweeping for phosphorus would be more effective in which of these: downtown Minneapolis, a high canopy area in St. Paul, a new development in Maple Grove
A high canopy area in St. Paul, due to the importance of organic material as a source of dissolved P
- Reasons why stormwater ponds export phosphorus include which of the following (select all that apply): turn over too frequently, turn over too infrequently, oxygen exists in the hypolimnion, inadequate maintenance, excess organic material entering the pond, excess canopy cover adjacent to pond prevents mixing
Ponds that turn over infrequently, that are poorly maintained, that have high organic inputs, and that are shaded and therefore not mixed have a greater tendency to export P
- True or false: Biochar is effective at absorbing phosphorus
False. Biochar does not appear to leach P, but it has not been show to absorb P.
- At about what % compost will bioretention media begin to leach phosphorus: 5, 10, 20
We aren't sure what the cutoff is yet, but research suggests compost concentrations of greater than 5% in bioretention media will leach P.
- True or false: Infiltration of stormwater runoff is an excellent method for reducing phosphorus loading to surface water
True. P is attenuated in the unsaturated zone and in groundwater
- True or false: in residential areas, runoff from surfaces considered to be permeable is an important source of dissolved phosphorus
True. Runoff from frozen soils and overirrigated lawns are considered important sources of dissolved P, though more research is needed to quantify these sources.
a
This page provides guidance related to assessing the total suspended sediment (TSS) and total phosphorus (TP) removal efficiency of permittee owned/operated ponds constructed and used for the collection and treatment of stormwater. Four (4) evaluation strategies are discussed.
- Evaluation of Minnesota Pollution Control Agency (MPCA) stormwater pond design criteria
- Stormwater pond inspection/assessment
- Stormwater pond pollutant removal modeling
- Stormwater pond water quality monitoring
The TSS and TP removal efficiency of constructed stormwater ponds degrades over time due to the loss of storage volume to sedimentation and/or sediment phosphorus release. For this reason, it is critical that stormwater ponds be sized correctly for their contributing drainage area and that pond inspection and assessments be performed routinely to monitor sedimentation and identify potential maintenance needs. In addition to evaluating pollutant removal efficiency through comparison to design standards and evaluation of sedimentation, the water quality performance of stormwater ponds can be evaluated using various water quality modeling programs or measured directly through water quality monitoring.
Guidance presented will assist MS4s (Municipal Separate Storm Sewer System) evaluate the TSS and TP treatment effectiveness of ponds post-construction and over their design life. The adjacent table provides a summary of the four (4) TSS and TP removal efficiency evaluation strategies discussed within this memorandum.
TSS and TP Removal Efficiency Evaluation Strategies
b
c
d
A tour of the Minnesota Stormwater Manual content