Percent P Removed Via Non-Volume Reduction Treatment
Link to this table
| Particulate P | Dissolved P | |||
|---|---|---|---|---|
| Current | Proposed | Current | Proposed | |
| No underdrain | 0% | 0% | 0% | 0% |
| Elevated underdrain | 45% | Is soil P content tested to be < 36 mg/kg per Mehlich III test?
If yes, 40 % If no, 0% |
0% | Is soil P content tested to be < 36 mg/kg per Mehlich III 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’ Credit for approved P-sorbing soil amendments*? For iron enhanced soils, Imbrium or WTRs, additional 40% credit |
| Underdrain at the bottom | 91% | Is soil P content tested to be < 36 mg/kg per Mehlich III test?
If yes, 40 % If no, 0% |
0% | Is soil P content tested to be < 36 mg/kg per Mehlich III test?
If yes, 20 % If no, 0% Does the system include approved P-sorbing soil amendments*? For iron enhanced soils, Imbrium or WTRs, additional 40% credit |
| Internal Water Storage (IWS) | Is soil P content tested to be < 36 mg/kg per Mehlich III test?
If yes, 40 % If no, 0% |
Is soil P content tested to be < 36 mg/kg per Mehlich III test?
If yes, 20 % If no, 0% Does the system include approved P-sorbing soil amendments*? For iron enhanced soils, Imbrium or WTRs, additional 40% credit |
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Approved P sorption amendments:
- 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 (see Task 7 for examples of other P sorptive amendments currently being studied)