image of flow chart used for wiki
Flow chart sequence used for the wiki. Symbols match those in the pdf version of the flow chart. Additional boxes (footnotes) were created to avoid redundancy in the flow chart process. Click on the image to see the footnotes.

This page summarizes the structure used for the wiki version of the Design Sequence Flow Chart. While the box numbers in the .pdf version and in the wiki version do not fully align, both flow charts are functional in that they proceed through the flow chart and take you to the correct performance goal.

  • MIDS design sequence flow chart - Step 1 - Did you gather site information?
  • MIDS design sequence flow chart - Step 2 - Prior to using the flow chart, gather the following preliminary information.
    • Conduct site review
    • Define performance goal
  • MIDS design sequence flow chart - Step 3 - Define Performance Goal
    • New and redevelopement projects: Retain on site a volume of 1.1 inches from impervious surfaces
    • Linear projects: Retain on site the larger of 1.1 inches from all new, or 0.55 inches from all new and fully reconstructed impervious surfaces
  • MIDS design sequence flow chart - Step 4- Does the project create one acre or more of new and/or fully reconstructed impervious surfaces?
  • MIDS design sequence flow chart - Step 5 - MIDS performance goal does not apply (The project creates less than one acre of new and/or fully reconstructed impervious surfaces)
  • MIDS design sequence flow chart - Step 6 - Is the project linear?
  • MIDS design sequence flow chart - Step 7 - Are there restraints due to lack of available right-of-way, off-site drainage and/or rate control requirements?
  • MIDS design sequence flow chart - Step 8 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Step 9 - Select Flexible Treatment Option (FTO) 2
    • Provide documentation of offsite runon to project area
    • Provide documentation of lack of right-of-way
  • MIDS design sequence flow chart - Step 10 - Select FTO #3. Provide site survey, maps, regulations, and/or cost estimates documenting that meeting the original performance goal of FTO alternatives is not feasible in addition to other documentation as required by LGU.
  • MIDS design sequence flow chart - Step 11 - Are there zoning and land use requirements that make the Performance Goal not feasible?
  • MIDS design sequence flow chart - Step 12 - Is BMP relocation feasible?
  • MIDS design sequence flow chart - Step 13 - Is Flexible Treatment Option (FTO) 1 feasible?
  • MIDS design sequence flow chart - Step 14 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Step 15 - Is the site located in a DWSMA, wellhead protection area or within 200 feet of a drinking water well?
  • MIDS design sequence flow chart - Step 16 - Can a Local Government Unit (LGU) provide a higher level of engineering review to ensure a functioning system that prevents adverse impacts to groundwater?
  • MIDS design sequence flow chart - Step 17 - Are there existing or proposed structures or infrastructure that make the performance goal not feasible?
  • MIDS design sequence flow chart - Step 18 - Is BMP relocation feasible?
  • MIDS design sequence flow chart - Step 19 - Is Flexible Treatment Option (FTO) 1 feasible?
  • MIDS design sequence flow chart - Step 20 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Step 21 - Is karst present of the site?
  • MIDS design sequence flow chart - Step 22 - Can a local unit of government (LGU) provide a higher level of Karst#Investigation for karst areas|engineering review to ensure a functioning system that prevents adverse impacts to groundwater?
  • MIDS design sequence flow chart - Step 23 - Is karst present within 1000 feet of proposed BMP location?
  • MIDS design sequence flow chart - Step 24 - Is BMP relocation on-site to a location without karst feasible?
  • MIDS design sequence flow chart - Step 25 - Select Flexible Treatment Option (FTO) 2
    • No infiltration practices allowed
    • Explore non-infiltration volume reduction practices
    • Provide soil borings or report from a professional geologist or geotechnical engineer
  • MIDS design sequence flow chart - Step 26 - Is shallow groundwater or shallow bedrock present on site?
  • MIDS design sequence flow chart - Step 27 - Conduct detailed site investigation.
  • MIDS design sequence flow chart - Step 28 - Is there more than 3 feet of soil depth (More than 10 feet is preferred) from bottom of the BMP to bedrock and/or groundwater?
  • MIDS design sequence flow chart - Step 29 - Is BMP relocation onsite to avoid shallow groundwater and bedrock feasible?
  • MIDS design sequence flow chart - Step 30 - Can the BMP be raised?
  • MIDS design sequence flow chart - Step 31 - Select Flexible Treatment Option (FTO) 2
    • No infiltration practices allowed
    • Explore non-infiltration volume reduction practices
    • Provide soil borings or report from a professional geologist or geotechnical engineer
  • MIDS design sequence flow chart - Step 32 - Raise BMP enough to ensure 3 feet (preferably 10 feet) of soil between bottom of BMP and top of bedrock and groundwater
  • MIDS design sequence flow chart - Step 33 - Is there presence of contaminated soils and/or groundwater, or hotspot runoff?
  • MIDS design sequence flow chart - Step 34 - Can hotspot or contamination be isolated or remediated to mitigat risk of increased contamination?
  • MIDS design sequence flow chart - Step 35 - Select Flexible Treatment Option (FTO) 2
    • No infiltration practices allowed
    • Explore non-infiltration volume reduction practices
    • Provide Phase I or II ESAs or other documentation of potential contamination or hotspot runoff
    • Provide documentation of extent of contamination and remediation alternatives considered
  • MIDS design sequence flow chart - Step 36 - Are there very low infiltrating soils (<0.2 inches per hour) on site?
  • MIDS design sequence flow chart - Step 37 - Is BMP relocation on site to a higher infiltrating location feasible?
  • MIDS design sequence flow chart - Step 38 - Can the BMP be sized to drain dry within 48 hours (24 hours in locations that are tributary to trout streams)?
  • MIDS design sequence flow chart - Step 39 - Provide soil boring or infiltration test results documenting low-infiltrating soils
  • MIDS design sequence flow chart - Step 40 - Is Flexible Treatment Option (FTO) 1 (lower volume control standard) feasible, allowing the BMP to drain within 48 hours (24 hours in locations tributary to trout streams)?
  • MIDS design sequence flow chart - Step 41 - Select Flexible Treatment Option (FTO) 2
    • No infiltration practices allowed
    • Explore non-infiltration volume reduction practices
    • Provide soil boring or infiltration test results documenting low-infiltration soils
  • MIDS design sequence flow chart - Step 42 - Are there very high infiltrating soils (more than 8 inches per hour)?
  • MIDS design sequence flow chart - Step 43 - Is BMP relocation on site to a lower infiltrating location feasible?
  • MIDS design sequence flow chart - Step 44 - Can subgrade be modified to slow the rate of infiltration to less than 8 inches per hour?
  • MIDS design sequence flow chart - Step 45 - Select Flexible Treatment Option (FTO) 2.
    • No infiltration practices allowed
    • Explore non-infiltration volume reduction practices
    • Provide soil boring or infiltration test results documenting high-infiltration soils
  • MIDS design sequence flow chart - Step 46 - Are there adverse surface water hydrologic impacts from infiltration practices (e.g. impacting perched wetland)?
  • MIDS design sequence flow chart - Step 47 - Can the BMP be relocated onsite to avoid adverse hydrologic impacts?
  • MIDS design sequence flow chart - Step 48 - Would BMPs accommodating Flexible Treatment Option (FTO) 1 avoid adverse hydrologic impacts?
  • MIDS design sequence flow chart - Step 49 - Select FTO Alternative No. 2
    • Maximize infiltration BMPs to treat up to the 0.55 inch goal, if possible
    • Explore non-infiltration volume reduction practices
    • provide report documenting potential hydrologic impacts from infiltration on the site, prepared by a registered engineer, hydrologist, or wetland specialist
  • MIDS design sequence flow chart - Step 50 - Select FTO Alternative No. 1
    • Maximize infiltration BMPs to treat more than 0.55 inch goal if possible
    • Provide report documenting potential hydrologic impacts from infiltration on the site, prepared by a registered engineer, hydrologist, or wetlands specialist.
  • MIDS design sequence flow chart - Step 51 - Complete design using the following performance goals
    • New development projects - 1.1 inches from new impervious surfaces
    • Redevelopment projects - 1.1 inches from new impervious surfaces
    • Linear projects
      • 0.55 inches of runoff from the new and fully reconstructed impervious surfaces
      • 1.1 inches of runoff from the net increase in impervious area
  • MIDS design sequence flow chart - Step 52 - Do the following conditions apply?
    • Zoning and land use requirements make FTO 2 not feasible; and
    • The BMP cannot be relocated to accommodate zoning and land use restrictions
  • MIDS design sequence flow chart - Step 53 - Do the following conditions apply?
    • There are existing or proposed structures or infrastructure that make FTO 2 not feasible; and
    • BMP relocation is not feasible
  • MIDS design sequence flow chart - Step 54 Do any of the following conditions apply? (NOTE: If any condition applies, you do not need to answer the remaining questions.)
    • The site is located within a DWSMA, wellhead protection area or within 200 feet of a drinking water well and infiltration is not allowed by the LGU
    • Karst is present within 1000 feet of the site and the BMP cannot be relocated so that it is more than 1000 feet from karst
    • Shallow groundwater or shallow bedrock is present within 3 feet of the bottom of the BMP and the BMP cannot be relocated or raised in elevation to achieve a 3 foot or greater separation from bedrock or groundwater
    • Contaminated soil, contaminated groundwater, or hotspot runoff is present on the site and cannot be isolated or mitigated
    • Soils on the site have an infiltration rate of less than 0.2 inches per hour, the BMP cannot be relocated to areas with an infiltration rate greater than 0.2 inches per hour, and the BMP cannot be sized to drain within 48 hours (24 hours in locations that are tributary to trout streams)
    • Soils on the site have an infiltration rate greater than 8 inches per hour, the BMP cannot be relocated to an area with an infiltration rate lower than 8 inches per hour, and the subgrade cannot be modified to slow the infiltration rate to less than 8 inches per hour
    • If no, go to Step 60
  • MIDS design sequence flow chart - Step 55 - Do the following conditions apply?
    • There are existing or proposed structures or infrastructure that make FTO 2 not feasible; and
    • BMP relocation is not feasible
  • MIDS design sequence flow chart - Step 56 - Select Flexible Treatment Option (FTO) 2
    • No infiltration practices allowed
    • Explore non-infiltration volume reduction practices
    • Provide DWSMA or well location map
  • MIDS design sequence flow chart - Step 57 Do any of the following conditions apply? (NOTE: If any condition applies, you do not need to answer the remaining questions.)
    • The site is located within a DWSMA, wellhead protection area or within 200 feet of a drinking water well and infiltration is not allowed by the LGU
    • Karst is present within 1000 feet of the site and the BMP cannot be relocated so that it is more than 1000 feet from karst
    • Shallow groundwater or shallow bedrock is present within 3 feet of the bottom of the BMP and the BMP cannot be relocated or raised in elevation to achieve a 3 foot or greater separation from bedrock or groundwater
    • Contaminated soil, contaminated groundwater, or hotspot runoff is present on the site and cannot be isolated or mitigated
    • Soils on the site have an infiltration rate of less than 0.2 inches per hour, the BMP cannot be relocated to areas with an infiltration rate greater than 0.2 inches per hour, and the BMP cannot be sized to drain within 48 hours (24 hours in locations that are tributary to trout streams)
    • Soils on the site have an infiltration rate greater than 8 inches per hour, the BMP cannot be relocated to an area with an infiltration rate lower than 8 inches per hour, and the subgrade cannot be modified to slow the infiltration rate to less than 8 inches per hour
    • If no, go to Step 49
  • MIDS design sequence flow chart - Step 58 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Step 59 - Do the following conditions apply?
    • There are very high infiltrating soils (more than 8 inches per hour) on the site; and
    • BMP relocation to an area with lower infiltration rates is not feasible; and
    • The subgrade cannot be modified to slow the rate to less than 8 inches per hour.
  • MIDS design sequence flow chart - Step 60 - Do the following conditions apply?
    • There are adverse hydrologic impacts from infiltration practices; and
    • The BMP cannot be relocated to avoid adverse hydrologic impacts; and
    • BMPs accommodating FTO 1 would avoid adverse hydrologic impacts
  • MIDS design sequence flow chart - Step 61 - Are there existing or proposed structures or infrastructure that make Flexible treatment options#Flexible Treatment Option 1 (FTO #1)|Flexible Treatment Option 1 not feasible?
  • MIDS design sequence flow chart - Step 62 Do any of the following conditions apply? (NOTE: If any condition applies, you do not need to answer the remaining questions.)
    • The site is located within a DWSMA, wellhead protection area or within 200 feet of a drinking water well and infiltration is not allowed by the LGU
    • Karst is present within 1000 feet of the site and the BMP cannot be relocated so that it is more than 1000 feet from karst
    • Shallow groundwater or shallow bedrock is present within 3 feet of the bottom of the BMP and the BMP cannot be relocated or raised in elevation to achieve a 3 foot or greater separation from bedrock or groundwater
    • Contaminated soil, contaminated groundwater, or hotspot runoff is present on the site and cannot be isolated or mitigated
    • Soils on the site have an infiltration rate of less than 0.2 inches per hour, the BMP cannot be relocated to areas with a higher infiltration rate, and the BMP cannot be sized to drain within 48 hours (24 hours in locations that are tributary to trout streams)
    • Soils on the site have an infiltration rate greater than 8 inches per hour, the BMP cannot be relocated to an area with an infiltration rate lower than 8 inches per hour, or the subgrade cannot be modified to slow the infiltration rate to less than 8 inches per hour
    • If no, go to Step 49
  • MIDS design sequence flow chart - Step 63 - Do the following conditions apply?
    • There are adverse hydrologic impacts from infiltration practices; and
    • The BMP cannot be relocated to avoid adverse hydrologic impacts
  • MIDS design sequence flow chart - Step 64 - Select Flexible Treatment Option (FTO) 2
  • MIDS design sequence flow chart - Step 65 - Select Flexible Treatment Option (FTO) 2
  • MIDS design sequence flow chart - Step 66 - Is Flexible Treatment Option (FTO) 2 feasible?

This page was last edited on 8 December 2022, at 15:28.