Updated October 2026
Water quality compliance means collecting the samples your permit or drinking water rules require, having them analyzed by approved methods, and reporting results on time. Monitoring technology shows what happens between those compliance samples, so a problem is caught in hours instead of at the next lab result.
Which EPA water deadlines are coming up?
As of October 2026:
| Rule | What it requires | Key dates | Status |
|---|---|---|---|
| PFAS drinking water rule (PFOA, PFOS) | Limits of 4.0 parts per trillion each | Initial monitoring results due April 26, 2027; limits apply April 26, 2029 | Final rule. EPA proposed in May 2026 to let systems request an extension to April 26, 2031; not final |
| PFAS drinking water rule (PFHxS, PFNA, GenX, mixtures) | Limits for three more PFAS and a mixture measure | Same dates as above | EPA proposed in May 2026 to rescind these; not final |
| Lead and Copper Rule Improvements | Lead action level falls from 15 to 10 µg/L; service line inventory and replacement | Compliance begins November 1, 2027 | Final rule |
| UCMR 6 | Occurrence monitoring for 30 unregulated contaminants, including certain PFAS, at systems serving 3,300 or more people | Proposed July 1, 2026 | Proposed |
What do state regulators check in a monitoring audit?
Every sanitary survey of a public water system must evaluate monitoring, reporting and data verification, alongside source, treatment, distribution and operations. In practice, reviewers look at:
- Whether every required sample was collected on schedule, at the approved sites.
- Whether compliance samples were analyzed by a certified lab using approved methods.
- Calibration records for continuous analyzers, such as the five-day grab sample check for chlorine residual.
- Gaps in continuous monitoring data, and what was done while an instrument was down.
- Whether results and any required public notices went out on time.
Concerned about contaminants in your water?
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Order a Water Test →Which tools help utilities and industrial sites stay compliant?
- Certified laboratories analyze compliance samples using approved methods.
- Online analyzers and automated monitoring show what happens between compliance samples, so a problem is caught in hours instead of at the next lab result.
- Compliance and lab data software, such as LIMS platforms, schedules sampling, tracks chain of custody and prepares reports.
Where KETOS fits
KETOS SHIELD measures 36+ parameters on site, including heavy metals at parts per billion, and sends results to operators and SCADA as they are produced: pH and conductivity about every minute, inorganics and heavy metals about hourly. Results fall within ±10% of certified lab results, and the system calibrates itself.
In Georgia, Fulton County and KETOS are running a joint study with the Georgia Environmental Protection Division to evaluate continuous monitoring data for formal compliance reporting. Utilities using SHIELD include the City of Rio Rancho, the Southern Nevada Water Authority, the Metropolitan Sewer District of Greater Cincinnati and Fulton County. See real-time water quality monitoring for municipal utilities.
Common questions
Is the EPA PFAS limit still 4 parts per trillion?
Yes, for PFOA and PFOS, as of October 2026. EPA has proposed letting systems request more time, to April 26, 2031, and proposed rescinding the limits for PFHxS, PFNA, GenX and the mixture measure; neither proposal is final.
Can real-time monitoring data be used for compliance reporting?
Yes, where the method is approved for that use, such as continuous chlorine residual monitoring with regular grab sample checks. For most other parameters, compliance samples go to a certified lab today, and Georgia EPD is studying continuous data for compliance reporting with Fulton County and KETOS.
Sources: 40 CFR 141.900; Federal Register 2026-10085 and 2026-10086; 40 CFR 141 Subpart I; Federal Register 2026-13263; 40 CFR 142.16; 40 CFR 141.74.
Related Resources
Looking for technology that keeps you compliant around the clock? Learn how continuous water quality monitoring uses automated IoT solutions to generate audit-ready reports and real-time alerts.
