UCMR 5 Updates

Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) Cycle – Collection of National Occurrence Data


In accordance with section 1445 (a) (2) of the Safe Drinking Water Act (SDWA), the EPA is implementing monitoring programs for unregulated contaminants. These monitoring programs are amended every five years with the addition of new priority pollutants for which collection of national occurrence data is essential for the EPA to make a regulatory determination of these specific pollutants. Part of recent changes to SDWA by the inclusion of Section 2021 of America’s Water Infrastructure Act of 2018 (AWIA) clearly outlines the following:

  • All Public Water Supplies (PWS) serving between 3,300 and 10,000 customers will have to comply with the sampling and analysis requirements of pollutants for that particular UCMR cycle.
  • For PWSs serving less than 3,300 customers, a nationally representative sample will suffice regarding the data collection requirement of the UCMR cycle.
  • All PWSs serving a customer base of more than 10,000 people also will be included in the UCMR 5 data collection effort.

The proposed rules regarding UCMR 5 can be accessed here. The highlights of the proposed rules are:

  • This rule is specifically applicable for community water systems (CWS) and non-transient, non-community water systems (NTNCWS). The applicability of this rule is as follows:
    • CWS and NTNCWS serving more than 10,000 people are required to monitor for 29 per- and polyfluoroalkyl substances (PFAS) compounds and lithium.
    • CWS and NTNCWS serving between 3,300 and 10,000 customers will also need to monitor for these PFAS compounds and lithium based on availability of laboratory capability of analyzing this volume of analytical data.
    • Transient non-community water systems (TNCWSs) would not be required to monitor under this UCMR 5 revision.
    • The NAICS codes that are applicable for these specific PWS include 22310 and 924110.
  • The UCMR 5 cycle and its included provisions, these rules become effective starting October 23, 2021.
  • Under the statutory obligation of SDWA, the EPA shall pay the reasonable cost of such testing and laboratory analysis specifically for PWS serving 10,000 or fewer customers.
  • In the absence of adequate funds, the EPA will not proceed to promulgate this final rule that requires PWSs between 3,300 and 10,000 persons to monitor these pollutants as stated in the proposed rule.

The total cost of this proposed action is estimated at $21.1 million per year for the five-year effective period of the rule (2022-2026). The total program cost is estimated at $105.9 million for the five-year period. The EPA has also proposed an alternative UCMR 5 which includes only 800 systems (<10,000 customers) with the total program cost estimated at $65.9 million for the five (5) year period.


The EPA has also included several other alternative provisions. The first is monitoring Legionella pneumophila in addition to the 29 PFAS compounds and lithium for a total program cost estimated at $137.6 million. Legionella pneumophila is a naturally occurring bacteria in potable water known to cause serious lung infection in humans. This alternative provision also includes monitoring for haloacetonitriles in addition to the 29 PFAS compounds and lithium for a total program cost estimated at $142.2 million. The last alternative in this category includes monitoring for Legionella pneumophila and haloacetonitriles in addition to the 29 PFAS compounds and lithium for a total program cost estimated at $172.2 million.

Important Notes Regarding the UCMR 5 data collection cycle

  • Sampling will occur for four consecutive quarters over the duration of a 12-month period, and this is applicable at facilities served entirely by surface water, facilities served entirely or in part by groundwater under the direct influence of surface water, and facilities that are served by both surface and groundwater and/or groundwater under the direct influence of surface water during this duration.
  • Specifically for groundwater locations, sampling shall take place twice over the duration of the 12-month period for a total of two sampling events.
  • For the purpose of data collection, samples shall be collected at the entry point of a specific water distribution system. However, for multiple sources of water entrances, a representative sample may be collected for that particular distribution system.
  • The deadline for proposal submittals to the EPA for review and approval regarding groundwater representative monitoring plans is December 31, 2022.
  • For small PWSs (fewer than 10,000), the EPA proposes 90 days to post and approve analytical results in the EPA’s Safe Drinking Water Accession Review System. However, for large PWSs, this period is only 30 days.

At Draper Aden Associates, we are well poised to assist PWSs during every phase of the UCMR 5 cycle. Below is a breakdown of our services based on the UCMR 5 timeline:

  • The pre-sampling activities (PSA) are planned to occur in 2022 per the UCMR 5 proposed timeline. During this PSA timeline, the following tasks are required:
    • managing lab approval programs
    • organizing state monitoring sampling plans
    • organizing partnership agreements which are key to the successful implementation of this plan.
    • registering and taking inventory of the PWS Drinking Water Accessories and Review System
    • preparing and reviewing Groundwater Review Management Plans prior to submittal to the State
    • conducting additional outreach and other training activities
  • During the actual sampling period that is supposed to last between 2023-2025, specific tasks include:
    • compliance assistance effort
    • developing and implementing small systems monitoring plans
    • reviewing and sending post quarterly data to the National Contaminant Occurrence Data (NCOD) portal
  • For the post-sampling activity that is projected to occur in 2026, tasks include:
    • completing data reports and data upload to NCOD site in accordance with the regulatory requirements as stated in the UCMR 5 cycle
    • conducting resampling activities if required by the EPA

Steps For Implementation with Detection of PFAS

If PFAS compounds are detected in the source or treated water, Draper Aden is well equipped to assist the PWS in the investigation and remediation process. Our PFAS services include:

  • Performing investigative studies to detect known, potential, and unknown sources of PFAS in the source water and/or finished (treated) water.
  • Developing a PFAS Management Plan (PMP) document that will detail remedial action strategies to address PFAS contamination. This may include modification and implementation of a new Best Management Practices at the site.
  • Applying for State or Federal funding for the potential implementation of a PFAS treatment system to treat the source water.
  • Designing the PFAS treatment system and assisting in its implementation and initial operation.
  • Providing continued technical support to the operation of the PFAS treatment system through an annual contract service agreement.

For more information on PFAS, visit our PFAS Resource Center.