40 CFR § 503.23 - Pollutant limits (other than domestic septage).

§ 503.23 Pollutant limits (other than domestic septage).

(a)Active sewage sludge unit without a liner and leachate collection system.

(1) Except as provided in § 503.23 (a)(2) and (b), the concentration of each pollutant listed in Table 1 of § 503.23 in sewage sludge placed on an active sewage sludge unit shall not exceed the concentration for the pollutant in Table 1 of § 503.23.

Table 1 of § 503.23 - Pollutant Concentrations - Active Sewage Sludge Unit Without a Liner and Leachate Collection

Pollutant Concentration (milligrams per kilograms 1)
Arsenic 73
Chromium 600
Nickel 420

1 Dry weight basis.

(2) Except as provided in § 503.23(b), the concentration of each pollutant listed in Table 1 of § 503.23 in sewage sludge placed on an active sewage sludge unit whose boundary is less than 150 meters from the property line of the surface disposal site shall not exceed the concentration determined using the following procedure.

(i) The actual distance from the active sewage sludge unit boundary to the property line of the surface disposal site shall be determined.

(ii) The concentration of each pollutant listed in Table 2 of § 503.23 in the sewage sludge shall not exceed the concentration in Table 2 of § 503.23 that corresponds to the actual distance in § 503.23(a)(2)(i).

Table 2 of § 503.23 - Pollutant Concentrations - Active Sewage Sludge Unit Without a Liner and Leachate Collection System That Has a Unit Boundary to Property Line Distance Less Than 150 Meters

Unit boundary to property line Pollutant concentration 1
Distance (meters) Arsenic (mg/kg) Chromium (mg/kg) Nickel (mg/kg)
0 to less than 25 30 200 210
25 to less than 50 34 220 240
50 to less than 75 39 260 270
75 to less than 100 46 300 320
100 to less than 125 53 360 390
125 to less than 150 62 450 420

1 Dry weight basis.

(b)Active sewage sludge unit without a liner and leachate collection system - site-specific limits.

(1) At the time of permit application, the owner/operator of a surface disposal site may request site-specific pollutant limits in accordance with § 503.23(b)(2) for an active sewage sludge unit without a liner and leachate collection system when the existing values for site parameters specified by the permitting authority are different from the values for those parameters used to develop the pollutant limits in Table 1 of § 503.23 and when the permitting authority determines that site-specific pollutant limits are appropriate for the active sewage sludge unit.

(2) The concentration of each pollutant listed in Table 1 of § 503.23 in sewage sludge placed on an active sewage sludge unit without a liner and leachate collection system shall not exceed either the concentration for the pollutant determined during a site-specific assessment, as specified by the permitting authority, or the existing concentration of the pollutant in the sewage sludge, whichever is lower.