Percent P Removed Via Non-Volume Reduction Treatment.
Caution: NOTE: These percentages apply to the non-volume reduction portion of stormwater runoff. The volume reduction portion of stormwater runoff receives 100 percent credit for particulate and dissolved phosphorus.
Link to this table
| |
Particulate P |
Dissolved P |
| |
Current in MIDS calculator |
Proposed |
Current in MIDS calculator |
Proposed |
| No underdrain |
0% |
0% |
0% |
0% |
| Elevated underdrain |
45% |
Is soil P content tested to be < 30 mg/kg per Mehlich III (or equivalent) test?
|
0% |
Is soil P content tested to be < 30 mg/kg per Mehlich III (or equivalent) test?
- If no, 0%
- If yes, is there at least 2 feet of soil above the elevated underdrain? If yes, 20% credit,
- If no, credit = 0.2*x
- Where x = (soil depth above elevated underdrain) /2 feet
- Additional credit for approved P-sorbing soil amendments = 40 percent if one of the following conditions aapplies.
- 5% by volume elemental iron filings above IWS or elevated underdrain
- Minimum 5% by volume sorptive media above IWS or elevated underdrain
- Minimum 5% by weight water treatment residuals (WTR) to a depth of at least 10 cm (1/3 foot)
- Other P sorptive amendments with supporting third party research results showing P reduction for at least 20 year lifespan, P credit commensurate with research results
|
| Underdrain at the bottom |
45% |
Is soil P content tested to be < 306 mg/kg per Mehlich III (or equivalent) test?
|
0% |
Is soil P content tested to be < 30 mg/kg per Mehlich III (or equivalent) test?
Additional credit for approved P-sorbing soil amendments = 40 percent if one of the following conditions applies.
- 5% by volume elemental iron filings above IWS or elevated underdrain
- Minimum 5% by volume sorptive media above IWS or elevated underdrain
- Minimum 5% by weight water treatment residuals (WTR) to a depth of at least 10 cm (1/3 foot)
- Other P sorptive amendments with supporting third party research results showing P reduction for at least 20 year lifespan, P credit commensurate with research results
|
| Internal Water Storage (IWS) |
Not in calculator |
Is soil P content tested to be < 30 mg/kg per Mehlich III (or equivalent) test?
|
Not in calculator |
Is soil P content tested to be < 30 mg/kg per Mehlich III (or equivalent) test?
Additional credit for approved P-sorbing soil amendments = 40 percent if one of the following conditions applies.
- 5% by volume elemental iron filings above IWS or elevated underdrain
- Minimum 5% by volume sorptive media above IWS or elevated underdrain
- Minimum 5% by weight water treatment residuals (WTR) to a depth of at least 10 cm (1/3 foot)
- Other P sorptive amendments with supporting third party research results showing P reduction for at least 20 year lifespan, P credit commensurate with research results
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