Section 503.46 - Frequency of monitoring(a)Sewage sludge.(1) The frequency of monitoring for beryllium shall be as required in subpart C of 40 CFR part 61, and for mercury as required in subpart E of 40 CFR part 61.(2) The frequency of monitoring for arsenic, cadmium, chromium, lead, and nickel in sewage sludge fed to a sewage sludge incinerator shall be the frequency in Table 1 of § 503.46 . Table 1 of § 503.46 -Frequency of Monitoring-Incineration
| Amount of sewage sludge1 (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 Amount of sewage sludge fired in a sewage sludge incinerator (dry weight basis).
(3) After the sewage sludge has been monitored for two years at the frequency in Table 1 of § 503.46 , the permitting authority may reduce the frequency of monitoring for arsenic, cadmium, chromium, lead, and nickel.(b)Total hydrocarbons, oxygen concentration, information to determine moisture content, and combustion temperatures. The total hydrocarbons concentration and oxygen concentration in the exit gas from a sewage sludge incinerator stack, the information used to measure moisture content in the exit gas, and the combustion temperatures for the sewage sludge incinerator shall be monitored continuously.(c)Air pollution control device operating parameters. For sewage sludge incinerators subject to the requirements in subpart O of 40 CFR part 60, the frequency of monitoring for the appropriate air pollution control device operating parameters shall be the frequency of monitoring in subpart O of 40 CFR part 60. For all other sewage sludge incinerators, the appropriate air pollution control device operating parameters shall be at least daily.58 FR 9387, Feb. 19, 1993, as amended at 64 FR 42573, Aug. 4, 1999 Approved by the Office of Management and Budget under control number 2040-0157