Design sequence flow chart

This is intended to take you through a design sequence that allows you to determine the appropriate performance goal at a site. Follow the questions below sequentially to arrive at a performance goal appropriate for your site.

Preliminary information

Conduct site review

• Aerial Photos
• Topographic Maps
• County Soil Surveys
• County Geologic Atlas
• Local Groundwater Levels
• Soil Borings
• MPCA Listing of Potentially Contaminated Sites
• TMDLs
• Local water quality standards

Speak with Local Landowners or others knowledgeable about the site
Inspect Site

Define treatment goal

• Linear: 0.55 inches over impervious
• Nonlinear:

FLOW CHART

DWSMA

Is the site located in a DWSMA, wellhead protection area, or near a drinking well?

• Yes
• No

DWSMA1

• Select Flexible Treatment Option
• (FTO) Alternative No. 2
• Revise Treatment Goal
• No infiltration practices allowed
• Provide DWSMA or well location map

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Utilities, structures, land use requirements

Are there existing or proposed utilities, structures, or land use requirements (density, parking, setbacks, etc.) that make the Treatment Goal infeasible or cost prohibitive? yes Karst, shallow groundwater, shallow bedrock|no

Utilities1

Is BMP relocation possible? Karst, shallow groundwater, shallow bedrock|yes Utilities2|no

Utilities2

Are Flexible Treatment Option Alternatives number 1 or number 2 feasible? yes no

Utilities3

Investigate Off-Site Considerations:

1. Banking within watershed with goal of:

• Linear: 0.55 inches over impervious
• Nonlinear: 1.1 inches over impervious

1. Cash as determined by LGU

Provide site survey, maps, regulations, and/or cost estimates documenting infeasibility and cost-prohibitive nature of meeting the original Treatment Goal or FTO Alternatives

END

Utilities4

• Select Flexible Treatment Option Alternative No. 1 or No. 2
• Revise Treatment Goal
• Provide site survey, maps, regulations, and/or cost estimates documenting infeasibility and cost-prohibitive nature of meeting the original Treatment Goal

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