WOH CCR Guide

All community water systems serving at least 25 people or 15 year-round residential connections must prepare and distribute an annual CCR covering the prior calendar year. The report must reach all bill-paying customers, non-bill-paying residents, non-English speakers (where applicable), and the state primacy agency by July 1. Check your state's requirements, as deadlines and formats may be stricter than the federal baseline.

The CCR must include system identification and contact information, water sources, a table of all regulated contaminants detected in the prior year (showing MCL, MCLG, level detected, and typical sources), results of unregulated contaminant monitoring if required, violations summary, and mandatory health effects language for any exceedances. Special statements are required for systems with lead service lines, Cryptosporidium-positive source water, arsenic or nitrate exceedances, and immunocompromised populations.

The detected contaminants table is the report's core. Include contaminant name, MCL or treatment technique requirement, MCLG, detected level (or range if multiple samples), unit of measurement, sample date, and typical sources. If a contaminant was not detected, mark it "nd" or "not detected," or reference that a complete list is available on request. Ensure the highest detected value is clearly visible so readers can compare it to the MCL.

For any contaminant exceeding its MCL or action level, provide plain-language explanation of sources, potential health effects, and corrective actions underway. EPA provides standardized health effects language in 40 C.F.R. Part 141, Appendix A that satisfies regulatory requirements; you may modify it for clarity without reducing accuracy. Begin data collection immediately after January 1 to gather laboratory reports, field measurements, and violation records in time for timely report completion.