Table 1.2 Nitrate Monitoring Requirements System Monitoring type Source Sampling frequency Notes type GW Annual All CWS & Initial Routine SW or NTNCWS Quarterly Sampling GWUDI TNCWS Any Annual GW Continue Annual All CWS & Reduced Sampling NTNCWS SW or Results from 4 consecutive Annual GWUDI quarters must be < ½ MCL. TNCWS Any Continue Annual Must collect 4 GW May reduce to annual All CWSs consecutive quarterly sampling if results from 4 & samples following any consecutive quarters are < NTNCWs one sample that is > than Increased Sampling than ½ the MCL. SW or ½ the MCL > than ½ the MCL GWUDI TNCWS Any Continue Annual GW Compliance with the MCL Confirmation sample must All CWSs is determined by be collected within 24 hours Increased Sampling & averaging results of initial of the systems receipt of NTNCWs and confirmation the analytical results of first >MCL samples. sample. SW or GWUDI TNCWS Any Continue Annual Waivers Grandfathering and waivers not permitted. Code of Federal Regulation (§141.23(d)(1-5)); (§141.23(i)(3)) & (§141.23(f)(2))
Table 1.2 Nitrate Monitoring Requirements Monitoring type System type Source Sampling frequency Notes Initial Routine Sampling All CWS & NTNCWS GW Annual SW or GWUDI Quarterly TNCWS Any Annual Reduced Sampling All CWS & NTNCWS GW Continue Annual SW or GWUDI Annual Results from 4 consecutive quarters must be < ½ MCL. TNCWS Any Continue Annual Increased Sampling > than ½ the MCL All CWSs & NTNCWs GW Must collect 4 consecutive quarterly samples following any one sample that is > than ½ the MCL May reduce to annual sampling if results from 4 consecutive quarters are < than ½ the MCL. SW or GWUDI TNCWS Any Continue Annual Increased Sampling >MCL All CWSs & NTNCWs GW Compliance with the MCL is determined by averaging results of initial and confirmation samples. Confirmation sample must be collected within 24 hours of the systems receipt of the analytical results of first sample. SW or GWUDI TNCWS Any Continue Annual Waivers Grandfathering and waivers not permitted. Code of Federal Regulation (§141.23(d)(1-5)); (§141.23(i)(3)) & (§141.23(f)(2))