Washington Administrative Code
Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508)
Chapter 173-308 - Biosolids management
Section 173-308-160 - Biosolids pollutant limits
Current through Register Vol. 24-06, March 15, 2024
This section sets pollutant concentration limits and cumulative pollutant loading rate limits for biosolids that are applied to the land.
(1) Table 1. Table 1 of this section sets the maximum allowable concentration (ceiling limit) of pollutants in biosolids that are applied to the land. Sewage sludge that contains any pollutant listed in Table 1 of this section at a concentration greater than the allowable ceiling limit is not biosolids, is a solid waste, and may not be applied to the land.
(2) Table 2. Table 2 of this section sets the maximum quantities of pollutants that may be added to an area of land, also referred to as the cumulative pollutant loading rate. The cumulative pollutant loading rates in Table 2 apply when the concentration of any pollutant in biosolids that are applied to the land exceeds the allowable pollutant concentration limit in Table 3 of this section.
(3) Table 3. Table 3 of this section sets a lower pollutant concentration threshold which, when achieved, relieves the person who prepares biosolids and the person who applies biosolids, from certain requirements related to recordkeeping, reporting, and labeling.
TABLE 1 - CEILING CONCENTRATION LIMITS
POLLUTANT |
CEILING CONCENTRATION milligrams per kilogram (dry weight basis) |
Arsenic |
75 |
Cadmium |
85 |
Copper |
4300 |
Lead |
840 |
Mercury |
57 |
Molybdenum |
75 |
Nickel |
420 |
Selenium |
100 |
Zinc |
7500 |
TABLE 2 - CUMULATIVE POLLUTANT LOADING RATES
POLLUTANT |
CUMULATIVE POLLUTANT LOADING RATE kilograms per hectare (dry weight basis) |
Arsenic |
41 |
Cadmium |
39 |
Copper |
1500 |
Lead |
300 |
Mercury |
17 |
Nickel |
420 |
Selenium |
100 |
Zinc |
2800 |
TABLE 3 - POLLUTANT CONCENTRATION LIMITS
POLLUTANT |
LIMIT monthly average in milligrams per kilogram (dry weight basis) |
Arsenic |
41 |
Cadmium |
39 |
Copper |
1500 |
Lead |
300 |
Mercury |
17 |
Nickel |
420 |
Selenium |
100 |
Zinc |
2800 |
Statutory Authority: Chapters 70.95J and 70.95 RCW. 07-12-010 (Order 06-06), § 173-308-160, filed 5/24/07, effective 6/24/07. Statutory Authority: RCW 70.95J.020 and 70.95.255. 98-05-101 (Order 97-30), § 173-308-160, filed 2/18/98, effective 3/21/98.