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.