40 CFR 503.16: Frequency of monitoring.

(a) Sewage sludge. (1) The frequency of monitoring for the pollutants listed in Table 1, Table 2, Table 3 and Table 4 of § 503.13; the pathogen density requirements in § 503.32(a) and § 503.32(b)(2); and the vector attraction reduction requirements in § 503.33 (b)(1) through (b)(4) and § 503.33 (b)(7) through (b)(8) shall be the frequency in Table 1 of § 503.16.

Table 1 of § 503.16—Frequency of Monitoring—Land Application

Amount of sewage sludge 1 (metric tons per 365 day period) Frequency

Greater than zero but less than 290 Once per year.

Equal to or greater than 290 but less than 1,500 Once per quarter (four times per year).

Equal to or greater than 1,500 but less than 15,000 Once per 60 days (six times per year).

Equal to or greater than 15,000 Once per month (12 times per year).

1 Either the amount of bulk sewage sludge applied to the land or the amount of sewage sludge prepared for sale or give-away in a bag or other container for application to the land (dry weight basis).

(2) After the sewage sludge has been monitored for two years at the frequency in Table 1 of § 503.16, the permitting authority may reduce the frequency of monitoring for pollutant concentrations and for the pathogen density requirements in § 503.32(a)(5)(ii) and (a)(5)(iii).

(b) Domestic septage. If either the pathogen requirements in § 503.32(c)(2) or the vector attraction reduction requirements in § 503.33(b)(12) are met when domestic septage is applied to agricultural land, forest, or a reclamation site, each container of domestic septage applied to the land shall be monitored for compliance with those requirements.