Statutes, codes, and regulations
Washington Administrative Code
Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508)
Chapter 173-308 - Biosolids management
Section 173-308-900 - Appendix A - Procedure to determine the annual whole biosolids application rate

Wash. Admin. Code § 173-308-900

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Current through Register Vol. 24-20, October 15, 2024
Section 173-308-900 - Appendix A - Procedure to determine the annual whole biosolids application rate

When biosolids are sold or given away in a bag or other container for application to the land, and any of the pollutant concentration limits in Table 3 of WAC 173-308-160 are exceeded, the mathematical product of the concentration in the biosolids of each pollutant listed in Table 4 of WAC 173-308-160 and the annual whole biosolids application rate (AWBAR) must not cause the annual pollutant loading rate for the pollutant in Table 4 of WAC 173-308-160 to be exceeded. This appendix contains the procedure used to determine an AWBAR that does not cause the annual pollutant loading rates in Table 4 of WAC 173-308-160 to be exceeded. The relationship between the annual pollutant loading rate (APLR) for a pollutant and the annual whole biosolids application rate (AWBAR) is shown in equation (7).

APLR = C* AWBAR * 0.001

Equation (7)

Where:

APLR = Annual pollutant loading rate in kilograms per hectare per 365 day period.

C = Pollutant concentration in milligrams, per kilogram of total solids (dry weight basis).

AWBAR = Annual whole biosolids application rate in metric tons per hectare per 365 day period (dry weight basis).

0.001 = A conversion factor.

To determine the AWBAR, equation (7) is rearranged into equation (8):

APLR

- - - - - - - - - - - - - -

C * 0.001

AWBAR

=

Equation (8)

The procedure used to determine the AWBAR is presented below.

Procedure:

1.Analyze a sample of the biosolids to determine the concentration for each of the pollutants listed in Table 4 of WAC 173-308-160.
2.Using the pollutant concentrations from Step 1 and the APLRs from Table 4 of WAC 173-308-160, calculate an AWBAR for each pollutant using equation (8).
3.The correct AWBAR is the lowest AWBAR calculated in Step 2.

Wash. Admin. Code § 173-308-900

Statutory Authority: RCW 70.95J.020 and 70.95.255. 98-05-101 (Order 97-30), § 173-308-900, filed 2/18/98, effective 3/21/98.