(Created page with "*MIDS design sequence flow chart - Box 1 - Did you gather site information? *MIDS design sequence flow chart - Box 2 - Prior to using the flow chart, gather the follow...")
 
m
Line 112: Line 112:
 
**The BMP cannot be relocated to avoid adverse hydrologic impacts; and
 
**The BMP cannot be relocated to avoid adverse hydrologic impacts; and
 
**BMPs accomodating FTO 1 would avoid adverse hydrologic impacts
 
**BMPs accomodating FTO 1 would avoid adverse hydrologic impacts
 +
*[[MIDS design sequence flow chart - Box 61]] 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 reloacted 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 box 57
 +
*[[MIDS design sequence flow chart - Box 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 reloacted 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 Box 49

Revision as of 17:09, 6 February 2014

  • MIDS design sequence flow chart - Box 1 - Did you gather site information?
  • MIDS design sequence flow chart - Box 2 - Prior to using the flow chart, gather the following preliminary information.
    • Conduct site review
    • Define performance goal
  • MIDS design sequence flow chart - Box 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 - Box 4- Does the project create one acre or more of new and/or fully reconstructed impervious surfaces?
  • MIDS design sequence flow chart - Box 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 - Box 6 - Is the project linear?
  • MIDS design sequence flow chart - Box 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 - Box 8 - Can a reasonable effort to acquire all of the right-of-way be accomplished?
  • MIDS design sequence flow chart - Box 9 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Box 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 - Box 11 - Are there zoning and land use requirements that make the Performance Goal not feasible?
  • MIDS design sequence flow chart - Box 12 - Is BMP relocation feasible?
  • MIDS design sequence flow chart - Box 13 - Is Flexible Treatment Option (FTO) 1 feasible?
  • MIDS design sequence flow chart - Box 14 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Box 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 - Box 16 - Is infiltration in this location permitted by the LGU, owner and operator?
  • MIDS design sequence flow chart - Box 17 - Are there existing or proposed structures or infrastructure that make the performance goal not feasible?
  • MIDS design sequence flow chart - Box 18 - Is BMP relocation feasible?
  • MIDS design sequence flow chart - Box 19 - Is Flexible Treatment Option (FTO) 1 feasible?
  • MIDS design sequence flow chart - Box 20 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Box 21 - Is karst present of the site?
  • MIDS design sequence flow chart - Box 22 - Conduct detailed site investigation.
  • MIDS design sequence flow chart - Box 23 - Is karst present within 1000 feet of proposed BMP location?
  • MIDS design sequence flow chart - Box 24 - Is BMP relocation on-site to a location without karst feasible?
  • MIDS design sequence flow chart - Box 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 - Box 26 - Is shallow groundwater or shallow bedrock present on site?
  • MIDS design sequence flow chart - Box 27 - Conduct detailed site investigation.
  • MIDS design sequence flow chart - Box 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 - Box 29 - Is BMP relocation onsite to avoid shallow groundwater and bedrock feasible?
  • MIDS design sequence flow chart - Box 30 - Can the BMP be raised?
  • MIDS design sequence flow chart - Box 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 - Box 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 - Box 33 - Is there presence of contaminated soils and/or groundwater, or hotspot runoff?
  • MIDS design sequence flow chart - Box 34 - Can hotspot or contamination be isolated or remediated to mitigat risk of increased contamination?
  • MIDS design sequence flow chart - Box 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 - Box 36 - Are there very low infiltrating soils (<0.2 inches per hour) on site?
  • MIDS design sequence flow chart - Box 37 - Is BMP relocation on site to a higher infiltrating location feasible?
  • MIDS design sequence flow chart - Box 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 - Box 39 - Provide soil boring or infiltration test results documenting low-infiltrating soils
  • MIDS design sequence flow chart - Box 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 - Box 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 - Box 42 - Are there very high infiltratin soils (more than 8 inches per hour)?
  • MIDS design sequence flow chart - Box 43 - Is BMP relocation on site to a lower infiltrating location feasible?
  • MIDS design sequence flow chart - Box 44 - Can subgrade be modified to slow the rate of infiltration to less than 8 inches per hour?
  • MIDS design sequence flow chart - Box 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 - Box 46 - Are there adverse surface water hydrologic impacts from infiltration practices (e.g. impacting perched wetland)?
  • MIDS design sequence flow chart - Box 47 - Can the BMP be relocated onsite to avoid adverse hydrologic impacts?
  • MIDS design sequence flow chart - Box 48 - Would BMPs accomodating Flexible Treatment Option (FTO) 1 avoid adverse hydrologic impacts?
  • MIDS design sequence flow chart - Box 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 - Box 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 - Box 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 - Box 52 - Do the following conditions apply?
    • Zoning and land use requirements make FTO 2 not feasible; and
    • The BMP cannot be relocated to accomodate zoning and land use restrictions
  • MIDS design sequence flow chart - Box 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 - Box 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 reloacted 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
  • MIDS design sequence flow chart - Box 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 - Box 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 - Box 57 - 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 - Box 58 - Is Flexible Treatment Option (FTO) 2 feasible?
  • MIDS design sequence flow chart - Box 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 - Box 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 accomodating FTO 1 would avoid adverse hydrologic impacts
  • MIDS design sequence flow chart - Box 61 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 reloacted 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 box 57
  • MIDS design sequence flow chart - Box 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 reloacted 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 Box 49