MassDEP outlines 24‑hour Tier 1 public‑notice steps after lead action‑level exceedance

A Massachusetts Department of Environmental Protection Drinking Water Program staff member said the 24‑hour Tier 1 public‑notice requirement is triggered “as soon as the system learns that they have exceeded the lead ninetieth percentile,” and that public water systems must distribute the notice within 24 hours.

The guidance explains how a system determines a “90th percentile” lead result, when the requirement applies, what must appear in the notice and how systems must certify distribution. The instruction applies to Massachusetts community and nontransient noncommunity public water systems regulated under the Lead and Copper Rule revisions (LCRR).

Why it matters: the LCRR became the compliance rule on Oct. 16, 2024, and MassDEP says the Tier 1 24‑hour public‑notice requirement remains active despite temporary pauses to most other LCRR provisions. The notice is intended to alert consumers rapidly when laboratory results indicate the system’s 90th‑percentile lead concentration exceeds the action level.

MassDEP’s explanation of the 90th‑percentile calculation: after a system collects the required number of samples and receives certified laboratory results, it organizes results from lowest to highest and multiplies the number of samples by 0.9 to locate the 90th‑percentile sample. If that sample result is above the action level, the system has an exceedance. For systems required to collect five samples, MassDEP says the 90th percentile is calculated by averaging the highest and second‑highest results and using that average to determine exceedance.

The action level cited in the video remains 0.015 milligrams per liter (15 parts per billion) through November 2027. MassDEP instructs systems to calculate the 90th percentile as soon as the last certified result is received and notes systems are “strongly encouraged” to do so immediately to protect public health.

Required content and templates: MassDEP requires use of an approved Tier 1 public‑notice template, available on the agency’s public notification forms and templates webpage. The template contains mandatory health effects language, a description of what happened and when, recommended consumer actions (including whether to use an alternative water supply), what the system is doing to address the exceedance, an expected resolution timeframe, contact information for the water system owner/operator or designee, and a statement asking recipients to share the notice with others.

Distribution methods and timing: MassDEP says the notice must be delivered in a manner reasonably calculated to reach all persons served, including residential and transient customers. Approved delivery methods include radio, television (using the same broadcast outlets used for public health orders), reverse 911, hand or direct delivery, and conspicuous posting. MassDEP cautions that local cable access TV alone is not sufficient. Community systems must also publish the Tier 1 notice as a one‑day newspaper advertisement no later than 14 days after the exceedance; smaller systems serving single buildings may request approval to use a local newsletter instead.

Preapproval and emergency procedures: systems are required to have their notice approved by MassDEP and the regional office prior to distribution when possible. Because the 24‑hour clock applies even after hours and on weekends, MassDEP requires systems (as of Oct. 16, 2024) to include a drafted Tier 1 notice in their emergency response plan (ERP) so MassDEP can review or preapprove it ahead of an exceedance. If a system cannot reach regional staff, it may call MassDEP’s 24‑hour emergency number at (888) 304‑1133.

Reporting and certification: within 24 hours of learning of an exceedance, systems must send a copy of the finalized notice to MassDEP and EPA (program.director‑twp@mass.gov and ledale@epa.gov) and cc regional staff. Community systems must certify distribution within 10 days after publishing the newspaper advertisement; nontransient noncommunity systems must certify within 10 days after issuing the public notice. The certification form is on MassDEP’s public notification forms page, and hard copies must be delivered to the regional office (electronic copies may also be sent).

Other compliance notes: the video reiterates that systems must still meet the public‑education requirements under the Lead and Copper Rule (LCR) and that other LCR requirements remain in force. MassDEP recommends systems with prior elevated 90th‑percentile values or values near the action level discuss draft notices and distribution plans with the regional office in advance to speed response.

Contact and forms referenced in the video include MassDEP DWP, the LCRR and LCRI documents, Form LCRD or LCRE for reporting, the MassDEP public notification templates webpage, the MassDEP emergency phone number (888‑304‑1133) and the two reporting email addresses cited above.

MassDEP’s video includes two template lengths — a short spoken version for radio/TV and a longer written version for hand delivery and newspapers — and notes that systems may change nonmandatory template text only with MassDEP approval. The agency also provided two scenarios in the video illustrating preapproval and weekend‑result situations to show how systems should proceed.

The video ended with a reminder to notify local health care providers so they can prepare to respond to questions from patients.