WAC 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.