M/DBP
Stakeholder Meeting:
Information Collection Rule Data Analysis
EXECUTIVE SUMMARY
M/DBP Stakeholder Meeting:
Information Collection Rule Data Analysis
November 20-21, 1997
In support of the Information Collection Rule (ICR) (61 FR 24354) EPA
held a stakeholder meeting on November 20-21, 1997, in Washington DC,
to present the Agency's draft ICR Data Analysis Plan. The purpose of the
draft plan is to provide an outline of an approach for evaluating the
ICR data in the context of the information needed for evaluating the potential
impacts from the Stage 2 Disinfectants/ Disinfection Byproduct Rule (D/DBPR)
and the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR).
The purpose of the stakeholder meeting was to present the Agency's draft
plan and begin a collaborative process to develop a more detailed plan
for ICR data analysis and data retrieval.
Background
The ICR was promulgated on May 14, 1996 and was intended to provide EPA
with information on the occurrence in drinking water of disinfection by-products
(DBPs) and pathogens as well as information on current treatment practices.
The primary goal of the ICR is to fill data gaps identified during the
regulatory negotiation process for the Stage 1 D/DBPR and Interim ESWTR.
The ICR data will specifically support the development of the Stage 2
D/DBPR and the LT2ESWTR.
The ICR requires all systems serving at least 100,000 people and ground
water systems serving at least 50,000 people to collect information on
the occurrence of DBPs and microbial pathogens in drinking water and treatment
information depending upon size and type of source water used. Additionally,
depending upon water quality conditions, systems are required to conduct
bench- and pilot-scale treatment studies to determine the effectiveness
of granular activated carbon (GAC) and membranes for reducing DBP precursors
(naturally occurring compounds that react with disinfectants to form DBPs).
Utilities began collecting ICR data in July 1997. The first six months
of QA/QC'ed data will be available in December 1998. The full 18 months
of QA/QC'ed data will be available in December 1999. The ICR treatment
study data will likely be available August 1999. The final Stage 2 D/DBPR
and the LT2ESWTR will be promulgated in May 2002.
Summary
EPA presented an overview of the data being collected under the ICR and
its role in supporting regulatory development. EPA then presented an overview
of the Draft ICR Data Analysis Approach. The suggested approach included
an initial characterization of baseline conditions after the ICR is completed
followed by predictions for occurrence and treatment changes following
implementation of the Stage 1 D/DBPR and the IESWTR. This new baseline
of information would eventually be used to evaluate different general
regulatory structures for the Stage 2 D/DBPR and the LT2ESWTR as part
of the next round of regulatory negotiations.
The meeting focused primarily on the characterization of baseline treatment
and occurrence conditions. The approach taken was to divide the data into
three categories: source water, treatment processes, and distributed water
(which includes finished water). For each of these three categories for
DBP data and for the first two categories for microbial data, major and
detailed questions were identified which the ICR data will be useful in
answering.
For DBPs, the source water questions pertain to the occurrence of DBP
precursors and water quality parameters related to DBP formation. The
major question for microbial source water characterization refers to the
levels of pathogens in source water. The issue of using an adjustment
factor for the microbial data was deferred to a latter time. Both the
DBP and microbial analyses require a characterization of the treatment
processes in place. The primary question identified for the distributed
water pertains to the levels of DBP occurrence. A number of more detailed
questions were presented by EPA and identified by stakeholders at the
meeting.
In addition to the baseline characterization, EPA presented an number
of predictive tools that could be used to forecast occurrence and treatment
conditions resulting from the Stage 1 D/DBPR and the IESWTR. These tools
were modeling and Delphi approaches, including case study approach, cumulative
probability approach, and a Monte Carlo approach. It was recognized that
development of a water treatment plant model similar to that used in the
first regulatory negotiation would need to begin immediately in order
for it to be of use in analyzing the ICR data when it becomes available.
A number of other useful statistical data analysis techniques were identified
by stakeholders including bootstrapping and jackknifing.
EPA also presented a plan for general public access to the ICR data over
the internet. EPA proposed quarterly or monthly updates of data accompanied
by purpose and limitation statements. Concerns were raised that ICR microbial
data be made available to the health community immediately if microbes
were found in the source water. Since a broader range of stakeholders
was desired for this discussion, it was decided to hold another stakeholder
meeting in the near future to address this issue.
Next Steps
One of the objectives of this stakeholders meeting was to identify next
joint requirements planning (JRP) steps for ICR data retrieval and analysis.
The group decided to create three technical work groups (TWGs): microbial,
DBPs, and modeling, with a steering committee consisting of a subset of
these TWGs. Each group will consist of interested stakeholders, EPA staff,
and data analysts/ programmers. The steering committee will meet to discuss
the TWG/JRP process on December 1 and 11. The first TWG/JRP meeting will
be on December 17, 1997. At this meeting the TWGs will identify further
questions for data analysis, articulate these needs to the data analysts,
and identify overlapping requirements between the different TWGs. Over
the next month the TWGs will send their draft questions out for comment
to the stakeholders and will meet on January 29-30 to finalize the draft
data analysis request. The TWGs will meet again on February 18 to prepare
for the February 19 stakeholder meeting in which the information needs
identified by the TWGs will be discussed. In March, a JAD will be held
in which the TWGs will refine their requirements for design and communicate
their needs to the programmers/ data analysts. In response, the programers
will identify what can be done by when.
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