UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C, 20460
FEB 13 207
MEMORANDUM
SUBJECT:
FROM:
TO:
Safe Drinking Water Act - Compliance Monitoring Transition Period between the
Stage 1 and Stage 2 Disinfectants and Disinfection Byproducts Rules and
Extension Requests
Ann Codrington, Director
Drinking Water Protection
Office of Ground Water and Drinking Water
Mark Poll ins, Director
Water Enforcement Division
Office of Civil Enforcement
Messina, Acting Directorf^j\^A^ (6~^ W-**-*
Monitoring, Assistance and Media Programs Division
Office of Compliance
Drinking Water Regional Managers and
Drinking Water Enforcement Regional Managers
Regions I-X
This memorandum provides states and EPA Regions with guidance for the compliance
monitoring period between the Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage
1), 40 C.F.R. §§ 141.130 - 135, and the Stage 2 Disinfectants and Disinfection Byproducts Rule
(Stage 2), 40 C.F.R. §§ 141.620 - 629. The memorandum discusses calculating the maximum
contaminant levels (MCLs) to determine compliance during the time period that systems are
transitioning from Stage 1 to Stage 2, and properly reporting violation and enforcement data to
the Safe Drinking Water Information System federal version (SDWIS/FED). In addition, this
memo provides guidance for notifying the public of existing Stage 1 violations during this
period. It also provides related guidance about extension requests for capital improvements under
§ 1412(b)(10) of the Safe Drinking Water Act (SDWA).
Background
All community water systems (CWSs) and non-transient non-community water systems
(NTNCWSs) that add a primary or residual disinfectant other than ultraviolet (UV) light must
comply with Stage 1. Stage 2 applies to all CWSs and NTNCWSs that use or deliver a primary
or residual disinfectant other than UV light, or receive water that has been treated with a primary
Printed on Recycled Paper
-------
or residual disinfectant other than UV light (i.e., consecutive systems). Federal regulations at 40
C.F.R, §§ 141.132 and 141.621 for Stage 1 and Stage 2 both require monitoring for total
trihalomethanes (TTHM) and five haloacetic acids (HAAS) to determine compliance with
maximum contaminant levels (MCLs). Stage 1 requirements specify compliance monitoring
locations in the distribution system (maximum residence time locations for all systems and
average residence time locations for some systems). Under Stage 1, TTHM and HAAS MCL
compliance is based on the calculation of a system-wide running annual average (RAA). Stage 2
changes how MCL compliance for TTHM and HAAS are calculated and also changes sample
site collection criteria, but not the MCL values, which remain at 80 ppb for TTHM and 60 ppb
for HAAS. This will result in some systems changing the number and/or location of compliance
monitoring sites.
Compliance with the MCLs for TTHM and HAAS under Stage 2 will be based on locational
running annual averages (LRAA) at compliance monitoring locations within the distribution
system. The LRAA calculation methodology is more stringent than the RAA approach because
when compliance is based on an RAA, samples with high TTHM or HAAS concentrations in one
part of the distribution system can be masked by samples with low TTHM or HAAS
concentrations in another part of the distribution system. The LRAA provides more equitable
public health protection for all consumers because all monitoring sites in the distribution system
must meet the TTHM and HAAS MCLs. Since the LRAA is calculated at each monitoring site
under Stage 2 rather than averaging all RAAs system-wide, multiple LRAAs will be calculated
for a system during every compliance period. During one compliance period, a public water
system may have one or more sample locations that exceed the MCL in accordance with the
LRAA compliance calculation in the regulation.
Primacy agencies should continue to encourage systems to use Initial Distribution System
Evaluation (IDSE) data and Stage 1 data in preparing for Stage 2 compliance monitoring. Stage
2 requires some systems to complete an IDSE to characterize the disinfection by-products
(DBFs) levels in their distribution systems and identify HAAS and TTHM Stage 2 compliance
monitoring locations. IDSE and Stage 1 data can assist a system in determining if treatment or
distribution changes are needed to achieve Stage 2 compliance.
It should also be noted that CWSs and NTNCWs must continue complying with Stage 1
maximum residual disinfectant levels (MRDLs), MCLs and DBF precursor removal
requirements, which Stage 2 does not change. In addition, all associated monitoring, reporting
and compliance calculations must continue to be met.
Transition to Stage 2 Compliance Monitoring
The period of time after Stage 2 monitoring is required to begin, but before TTHM and HAAS
compliance calculations can be made based on the LRAA, will be a transition period from Stage
1 to Stage 2. During the transition period, all recordkeeping requirements as described in 40
C.F.R. § 141.33 must continue to be met by systems.
Pursuant to the table in 40 C.F.R. § 141.620, systems will start compliance monitoring in
accordance with Stage 2 requirements beginning April 1, 2012 (or earlier based on primacy
-------
agency directive), but no later than October 1, 2014, with the specific monitoring period
dependent on system population and other factors. Once a system is required to begin Stage 2
quarterly compliance monitoring under 40 C.F.R. § 141.620(c), it will no longer be required to
perform monitoring pursuant to its Stage 1 TTHM and HAAS monitoring plan. Under Stage 2,
systems will perform four consecutive quarters of monitoring and will conduct compliance
calculations at the end of the fourth calendar quarter that follows the compliance date. Systems
will continue to conduct LRAA compliance calculations at the end of each subsequent quarter.
(Please note a violation can be incurred earlier if the LRAA calculated based on fewer than four
quarters of data would exceed the MCL). If a system is required to conduct monitoring at a
frequency that is less than quarterly and its first Stage 2 compliance sample is greater than the
MCL, then the system must initiate quarterly monitoring and perform LRAA compliance
calculation(s) after four consecutive quarters,
Public Notice of Existing Stage 1 MCL Violations during the Transition Period
The Public Notification (PN) rule requirements of 40 C.F.R. § 141.202-204 continue during the
transition period between Stage 1 and Stage 2. Specifically, 40 C.F.R. § 141.203(a)(l) of the PN
rule requires Tier 2 public notice when a system exceeds a TTHM and/or HAAS MCL under
Stage 1 or Stage 2 along with Tier 3 public notice for monitoring and reporting (M&R)
violations of either rule. Accordingly, any activities associated with existing Stage 1 MCL
violations, including the PN requirements under Subpart Q, are ongoing. Additionally, a CWS
must include in its yearly consumer confidence report (CCR) the range of jjj-ijvi and HAAS
individual sampling results during the transition period.
Systems in violation of the TTHM and/or HAAS MCL using Stage 1's RAA immediately before
and during the transition period to Stage 2 must provide notification to their consumers that the
system is in violation until a Stage 2 MCL compliance determination has been made. 40 C.F.R.
§ 141.203(b)(2). As part of the PN, EPA recommends a system explain that it is
collecting/evaluating new data before determining compliance with the MCL using the LRAA.
The explanation should also detail a system's actions in addressing its TTHM and/or HAAS
levels, including the use of Stage 2 data to make improved treatment decisions (e.g., data may
identify an area in the distribution system with extended water age that the system can then
address using water age management). Once the Stage 2 MCL compliance determination has
been made and if it shows no exceedance of the Stage 2 MCL, then public notice for the Stage 1
violation is no longer necessary. However, if the Stage 2 MCL has been exceeded, Tier 2 public
notice will be required for the Stage 2 MCL violation. 40 C.F.R. § 141.203(b)(2).
EPA's Drinking Water Enforcement Response Policy and Enforcement Targeting Tool
In December 2009, EPA issued the Drinking Water Enforcement Response Policy (ERP). The
ERP is an approach that replaces the contaminant-by-contaminant strategy with one that
examines all the violations of a public water system. The purpose of the ERP is to help states
and EPA focus enforcement attention on public drinking water systems with the most serious
and/or repeat violations, including noncompliance with Stage 1 and Stage 2 requirements.
The Enforcement Targeting Tool (ETT) under the new ERP uses data in the SDWIS/FED to
generate a score for each public water system with at least one unresolved violation in the past
five years. The ETT assigns points for each violation based upon the severity of the violation
-------
and the length of time for the oldest unresolved violation, producing a quarterly aggregate score
for each noncornplying public water system. The ETT allows noncomplying systems to be
ranked according to severity and length of time since the unresolved violations. Primacy
agencies directly implementing Stage 1 and Stage 2 must continue to report violation and
enforcement data into SDW1S/FED to help ensure a complete and accurate picture for each
public water system subject to the rules.
Questions have been posed by primacy agencies about the proper way to code Stage 1 MCL and
M&R violations in SDW1S/FED that have not been returned to compliance before Stage 2
compliance monitoring begins. A system's Stage 1 and Stage 2 compliance monitoring locations
may differ; however, due to the required Stage 2 location selection process, the Stage 2 sites are
more protective of public health. For this reason, Stage 2 compliance monitoring locations will
be used to determine when to close existing Stage I TTHM and/or HAAS MCL and M&R
violations in SDWIS/FED, as outlined below.
Once a system begins to implement Stage 2 and makes its TTHM and/or HAAS MCL(s)
compliance determinations using the LRAA, a primacy agency may begin reporting any new
Stage 2 MCL violation(s) and code any existing Stage 1 MCL violation(s) with resolving action
codes SO6 (state intentional no action) or EO6 (federal intentional no action). Further, primacy
agencies should only code open Stage 1 M&R violations with resolving action codes SO6 or
E06 after the system demonstrates one quarter of compliance with Stage 2 M&R requirements.
SO6 and EO6 indicate that no further enforcement response is being taken at this time for the
corresponding violation. These SDWIS/FED codes in the above prescribed manner should only
be used during the transition period. It is not appropriate for a primacy agency to use the SOX
(state compliance achieved) and/or EOX (federal compliance achieved) codes for any open Stage
1 MCL violations that have not been returned to compliance before the Stage 2 compliance
monitoring transition begins.
MCL Compliance Extensions for Capital Improvements
In accordance with § 1412(b)(10) of the SDWA and regulations at 40 C.F.R. § 141.620(c), a
state or EPA may grant an individual system an extension of up to two additional years to
comply with an MCL or treatment technique if the state or EPA determines the system needs
additional time for capital improvements. A system subject to Stage 2 should have sufficient
information (e.g., IDSE, Stage 1 Rule, and/or operational monitoring data) to determine whether
a request for an extension from its primacy agency is appropriate, because the system may have
difficulty complying with Stage 2. As described in the Stage 2 DBPR Implementation Guidance
Manual, Appendix I, the state should consider whether there has been a "good faith" effort on the
part of the system submitting the extension request. A request for an extension under SDWA §
1412(b)(10) should not be an "eleventh-hour" effort by a system to avoid potential violations.
Furthermore, a system requesting a SDWA § 1412(b)(10) extension should notify and inform its
customers, and thereby provide an opportunity for the customers to provide input to the
state/primacy agency about the extension.
In addition, it should be noted that a wholesaler's extension request application does not
automatically extend to its consecutive system(s). It is recommended that a consecutive system
work with its wholesaler to coordinate extension request applications. A system that submits an
-------
extension request that does not allow sufficient time for primacy agency consideration ahead of
the compliance deadline (i.e., not in "good faith") risks incurring violations until the state has
made a determination on the system's request.
Appendix I of the implementation guidance provides information for how a state or EPA should
evaluate an extension request. Appendix I also includes recommendations for what to consider
during the review (e.g., duration of extension including a schedule, critical milestones, and a
final deadline) and best management practices the system should use to ensure the highest
quality drinking water is delivered during the extension period. Often the conditions for the
extension will be refined through negotiations between a water system and a primacy agency.
While establishing the conditions for the extension, the state and water system should discuss
and document the implications of missed milestones (e.g., violations of the National Primary
Drinking Water Regulations) and how to resolve any deviations. EPA recommends the state
document in writing the conditions of the extension.
A SDWA § I412(b)(10) extension only applies for the period negotiated between the state/EPA
and the system. The system must still comply with all other provisions of the Stage 2 Rule (e.g.,
M&R requirements). Compliance determinations for TTHM and HAA5 during the extension
period will be based on an RAA of the samples collected at the Stage 2 compliance monitoring
locations. Please note that a SDWA § 1412(b)(10) extension does not preclude a water system
from incurring TTHM or HAAS MCL violations. During the extension period, MCL violations
of the TTHM and HAAS based on a RAA of the samples collected must be documented
appropriately in SDW1S FED. Once the system completes its capital improvements agreed upon
in the extension, it must monitor for four quarters at the Stage 2 compliance monitoring locations
before making its first LRAA compliance determinations, and at the end of each subsequent
quarter (or earlier if the LRAA calculated based on fewer than four quarters of data would cause
the MCL to be exceeded). If a system is required to conduct monitoring at a frequency that is
less than quarterly, it must make compliance calculations beginning with its first Stage 2
compliance sample.
If you have additional questions about Stage 1 and Stage 2, please contact OGWDW's Adrienne
Harris at 202-250-8793, or OECA's Carol DeMarco at 202-564-2412 or Joyce Chandler at 202-
564-7073.
cc: Jim Taft, ASDWA
MDBP Implementation Workgroup
SDWA Enforcement Coordinators
------- |