40 CFR § 141.564 - My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring?

---
identifier: "/us/cfr/t40/s141.564"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 141.564 - My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring?"
title_number: 40
title_name: "Protection of Environment"
section_number: "141.564"
section_name: "My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring?"
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "D"
subchapter_name: "WATER PROGRAMS"
part_number: "141"
part_name: "NATIONAL PRIMARY DRINKING WATER REGULATIONS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, and 300j-11."
regulatory_source: "40 FR 59570, Dec. 24, 1975, unless otherwise noted."
cfr_part: "141"
---


# 141.564 My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring?

If your system utilizes lime softening, you may apply to the State for alternative turbidity exceedance levels for the levels specified in the table in § 141.563. You must be able to demonstrate to the State that higher turbidity levels are due to lime carryover only, and not due to degraded filter performance.