---
kind: "section"
citation: "40 C.F.R. § 503.16"
title: "40"
number: "503.16"
heading: "Frequency of monitoring."
url: "https://uscodex.org/cfr/40/503.16"
---

# §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](/cfr/40/503.13.md); the pathogen density requirements in [§ 503.32(a)](/cfr/40/503.32.md?p=a) and [§ 503.32(b)(2)](/cfr/40/503.32.md?p=b-2); and the vector attraction reduction requirements in [§ 503.33 (b)(1) through (b)(4)](/cfr/40/503.33.md?p=b-1..b-4) and [§ 503.33 (b)(7) through (b)(8)](/cfr/40/503.33.md?p=b-7..b-8) shall be the frequency in Table 1 of § 503.16.
  - (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)](/cfr/40/503.32.md?p=a-5-ii) and [(a)(5)(iii)](/cfr/40/503.32.md?p=a-5-iii).
- (b) **Domestic septage.** If either the pathogen requirements in [§ 503.32(c)(2)](/cfr/40/503.32.md?p=c-2) or the vector attraction reduction requirements in [§ 503.33(b)(12)](/cfr/40/503.33.md?p=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.

## Notes

### Amendments

[58 FR 9387, Feb. 19, 1993, as amended at 64 FR 42569, Aug. 4, 1999]

### Authority

Authority: Sections 405 (d) and (e) of the Clean Water Act, as amended by Pub. L. 95-217, sec. 54(d), 91 Stat. 1591 (33 U.S.C. 1345 (d) and (e)); and Pub. L. 100-4, title IV, sec. 406 (a), (b), 101 Stat., 71, 72 (33 U.S.C. 1251 et seq. ).

### Source

Source: 58 FR 9387, Feb. 19, 1993, unless otherwise noted.

### Amendments

[58 FR 9387, Feb. 19, 1993, as amended at 64 FR 42569, Aug. 4, 1999]