Water Testing


MNPS Drinking Water Testing Program

In 2016, Metro Nashville Public Schools (MNPS) embarked on an ambitious, first-ever, voluntary water testing program in the wake of the lead crisis in Flint, MI and other areas of the country. It wanted to make sure water in its schools was safe for students and staff.

What began as a two-year, two-phase water-quality testing program at MNPS, expanded into a dynamic and comprehensive water-quality testing and remediation program encompassing installation of new water fixtures, replacement of water lines, quarterly random water quality testing, monthly maintenance testing and flushing water lines after long breaks.

Here's a look back at what MNPS has accomplished since 2016.

Phase I

Summer 2016

Sampling and laboratory analysis of drinking water collected from 49 MNPS schools and administrative buildings identified by MNPS, prioritized based on relative age of facilities (older) and age of student bodies (younger). Based on initial Phase I results, additional sampling and analysis was performed as part of Phase I, and MNPS implemented corrective measures addressing drinking water taps where elevated lead concentrations were reported.

Phase II

Summer/Fall 2017*

Sampling and laboratory analysis of drinking water collected from additional MNPS schools and administrative buildings also based on older age of facilities and younger age of student bodies.

Phase III

July/early August 2017

Sampling and laboratory analysis of drinking water collected from 143 MNPS schools and administrative buildings. Based on results from previous phases of sampling and on initial Phase III results, additional sampling and analysis was performed and MNPS implemented corrective measures addressing drinking water taps where elevated concentrations were observed.

Phase IV


Phase IV was proactively initiated March 2018 and includes monthly sampling of water from taps that have previously shown concentrations of lead between 5 and 15 parts per billion (ppb) as well as annual maintenance sampling of select taps previously shown less than 5 ppb. The objective of the two ongoing programs is to help achieve an aggressive district-set goal of 5 ppb or less of lead in drinking water at MNPS facilities. Also as part of these programs, fixtures and taps where concentrations greater than 5 ppb have been removed or retrofitted to achieve less than 5 ppb. It should be noted a new State of Tennessee Law enacted January 1, 2019, and U.S. Environmental Protection Agency (U.S. EPA) guidance, indicate the current action levels for schools are 15 and 20 ppb, which are considerably higher (less stringent) than the MNPS goal of 5 ppb. As such, the programs proactively being performed by MNPS are considerably more protective than the current State and EPA programs. Review the MNPS water quality protocol.

* Phase II plans were incorporated into the accelerated Phase III testing

As mentioned above, the monthly sampling program focuses on water from taps where lead levels tested at concentrations between 5 and 15 ppb during the previous 2017 Phase III sampling. Out of 4,200 locations, an estimated 150 samples were in this range of lead concentrations based on previous Phase III results and many of those were only marginally above 5 ppb according to the third-party lab ENSAFE analyzing the samples. This current program includes monthly collection and analysis of water samples, as well as aggressively addressing fixtures where 5 ppb continue to be detected. Through periodic sampling and continued retrofitting or removal of fixtures where concentrations greater than 5 ppb are detected, concentrations of 5 ppb or less have been achieved in samples from the remaining fixtures.

Annual maintenance sampling focuses on randomly selected taps where lead concentrations were less than 5 ppb during previous Phase III activities. Based on review of historical sampling activities, more than 4,000 sampling locations are in this range of lead concentrations. Annual maintenance sampling involves collection and analysis of water from approximately 10 percent of the taps where these concentrations were previously reported. Random generator software is being used to select the taps to be sampled at each of the schools. Nearly 500 samples have been collected as part of this program, and lead concentrations in an estimated 98 percent remained less than 5 ppb. The few greater than 5 ppb were considerably below the State and U.S. EPA action level of 20 ppb.

MNPS knows continued testing and remediation is the right thing to do to provide the best water quality possible in schools. MNPS continues to work with Metro Water Services, Metro Public Health Department, the EPA, the Tennessee Department of Environment and Conservation and the third-party expert, ENSAFE, to develop and implement a process that meets all requirements for water quality sampling of public water systems. Water in all MNPS schools tested is safe and meets, and in most cases exceeds, all guidelines standards for public water systems.

There is no federal law requiring testing of drinking water in schools and childcare facilities - only recently Tennessee State law; however, EPA has developed a guidance manual to assist schools with lead in drinking water prevention programs. Click here to see the manual.

EPA Validates District's Lead Testing Protocol

"In response to your inquiry, the attached memorandum refers to regulated public water systems (PWS). Schools are served by PWSs, but are not regulated under the Lead and Copper Rule, thus the attached memorandum does not apply. The 3 T's guidance document contains recommendations for sampling and flushing of fixtures within schools and daycares." - EPA Region 4, Grants and Drinking Water Protection Branch, Drinking Water Section

Refer to the 3 T's guidance here.