Table 7.
The EPA Part 503 heavy metal requirements in biosolids applied to land.
| Type of Heavy Metal | Concentration limits for all biosolid types applied to land. (mg/kg)a | Concentration limits for exceptional quality (EQ) and pollutant concentration biosolids (mg/kg)a | Cumulative pollutant loading rate (CPLR) limits for biosolid (kg/ha) | Annual pollutant loading rate (APLR) for biosolids (kg/ha.yr) |
|---|---|---|---|---|
| Chromium | 3000 | 1200 | 3000 | 150 |
| Arsenic | 75 | 41 | 41 | 2.0 |
| Cadmium | 85 | 39 | 39 | 1.9 |
| Mercury | 57 | 17 | 17 | 0.85 |
| Lead | 840 | 300 | 300 | 15 |
| Copper | 4300 | 1500 | 1500 | 75 |
| Nickel | 420 | 420 | 420 | 21 |
| Molybdenumb | 75 | – | – | – |
| Zinc | 7500 | 2800 | 2800 | 140 |
| Selenium | 100 | 36 | 100 | 5.0 |
| Applies to: | All biosolids applied on land. | Bulk and bagged biosolids. | Bulk biosolids | Bagged biosolidsc. |
ab,c = Dry mass basis measurement; molybdenum limits were deleted from the Part 503 Rule after February 1994 amendment, awaiting EPA consideration; biosolids delivered in bags or other similar containers [159].