M/DBP Stage 2
Federal Advisory Committee (FACA2)
Stage 1 Baseline for large and small systems, Unit Technology Costs, Microbial
Occurrence and Discussion of Stage 2 Scenarios
Meeting Summary - March 2000
Meeting #9*
March 29-30, 2000
Washington, DC
*Note: The FACA meeting originally scheduled for February 2000 was canceled
Table of Contents
Introduction
Overview of Where We Are And Where We Are Going
Stage 1 Baseline: TWG Presentation
Microbial Framework for Filtered Systems
Unit Costs for Various Technologies
Examples of Stage 2 Scenarios Developed by TWG
Examples of Stage 2 Impacts To Non-ICR Systems
Framework and Examples To Discuss Stage 2 Scenarios
Scenarios for TWG Analysis and FACA Deliberation
Public Comment
Next Steps
ATTACHMENTS
I.a Meeting Participants - M/DBP FACA, March 29-30, 2000
I.b Meeting Agenda - MDBP FACA, March 29-30, 2000
II. Where We Are and Where Do We Need To Go? - Abby Arnold
III.a TWG Presentation to FACA Committee - Stage 1 Baseline, Michael
McGuire
III.b Non-ICR Systems Stage 1 Baseline Presentation to the FACA, Stig
Regli
IV.a Preliminary Microbial Options Based on FACA Questions and Potential
Framework for Filtered Systems - Stig Regli
IV.b Memorandum: Examination and Recommendations for EPA Programs on
Waterborne Microbial Disease
V. Technology and Costs for Disinfection and DBP Control - Douglas Owen
VI. TWG Presentation to FACA Committee, Stage 2 Examples - Michael McGuire
VII. Non-ICR Systems, Example Stage 2 Impacts Presentation to the FACA
- Stig Regli
VIII. Suggestions For How FACA Might Direct TWG - Ephraim King
Introduction
On January 29-30, 2000, EPA held the ninth meeting of the Stage 2 Disinfection
Byproducts and Long-Term 2 Enhanced Surface Water Treatment Rules (MDBP)
Federal Advisory Committee (FACA). Facilitator Abby Arnold, RESOLVE, began
the meeting with introductions from FACA members and reviewed the proposed
agenda and objectives of the meeting. The objective of this meeting was
to hear presentations by the TWG on the Stage 1 baseline for large and
small systems, unit technology costs, and microbial occurrence and options
for reducing levels of microbial pathogens in drinking water. The FACA
discussed various Stage 2 scenarios, direct the TWG for additional analysis,
and FACA members' preferred approaches and schedule for discussing scenarios.
See Attachment I.a for a list of meeting participants and Attachment I.b
for the draft meeting agenda.
Discussion of M/DBP FACA Groundrules.
Cynthia Dougherty, Director, Office of Groundwater Drinking Water, EPA
first stated that she did not blame any one at the table for the events
that have transpired with a lawsuit between US EPA and the Boston utility
Massachusetts Water Resources Authority (MWRA). She then went on to explain
that the FACA groundrules had been violated and that is why EPA cancelled
the February FACA meeting.(1)
Dougherty explained that she understood that the parties in the litigation
did what they believed was necessary to defend their case. The problem,
Dougherty pointed out, is that EPA's ability to act freely in the FACA
discussions is sincerely compromised to the extent that Dougherty is questioning
EPA's ability to continue to participate in the FACA process. EPA is now
constrained; all Office of Ground Water and Drinking Water (OGWDW) staff
must now submit microbial presentations and analysis to regional council
and DOJ prior to presentation to the FACA. This compromises OGWDW staff's
ability to take advantage of open and free sharing of information by the
FACA and TWG. Dougherty reiterated her commitment to the FACA process.
The benefit of the FACA process, stated Dougherty is the ability of its
members to problem solve in an informal discussion about difficult issues.
If EPA, or any other party around the table, has to worry about misuse
of informal discussion and dialogue, parties will shut down and will not
be able to talk openly. Dougherty pointed out that EPA staff at the table
are no longer able to respond informally to ideas discussed at the table.
To address the immediate situation and ongoing litigation in Massachusetts,
EPA is considering removing from the FACA's purview any discussion about
regulatory controls and barriers for unfiltered systems. If unfiltered
systems are taken off the table, EPA would develop unfiltered systems
rules through a separate stakeholder involvement process.
There was very thoughtful and considerable discussion among FACA members.
Comments pertained to 1) the value of the FACA process itself and 2) the
proposed remedy to remove discussion of unfiltered systems from the table.
Those who commented on the value of the FACA process pointed out that
the FACA is a robust process that has been and always will be fragile.
One member pointed out that it is a tribute to the process that it has
lasted so long (now three phases that began in 1993). This member further
pointed out that the groundrules provide the safeguards to the parties,
that there is no policing of the groundrules other than the good will
of the FACA members, interested parties and public. The members at the
table are bound to one other's good faith, and that each of the members
are at the mercy of all in the room. Enforcement of the groundrules depends
on everyone's willingness to take the fragility seriously and make certain
that the groundrules are adhered to seriously. This member further pointed
out that if parties carve out the process, one piece at a time, the process
will be less robust This member, as well as others, pointed out that the
proposed solution, that is taking the unfiltered systems issues off the
table could compromise the overall process.
FACA members discussed the proposal to not address unfiltered, a number
of the members were concerned that by taking unfiltered systems off the
table the benefit of full dialogue among a broad array of stakeholders,
each with a different perspective, would be lost. Other stakeholders were
concerned about their ability to have input and provide influence on unfiltered
systems issues if these issues were discussed in another forum. Some members
pointed out that they represent both filtered and unfiltered systems and
it would be difficult to separate their representation of these systems.
All who spoke agreed that regardless of the outcome of the unfiltered
systems proposal, FACA membership should not change. Ms. Dougherty and
Ms. Menard agreed to bring a proposal back to the FACA.
Overview of Where We Are And Where We Are Going
Abby Arnold, RESOLVE, presented an overview and proposed schedule for
this last phase of the FACA process March - July 2000. [see Attachment
II.] Arnold pointed out that in order to meet EPA's schedule for rule
development, the FACA must develop recommendations for the Stage 2 Rules
by end of June. There will be an additional FACA meeting on July 27 to
allow time for FACA members to consult with their constituents and sign
the Stage 2 agreement.
To meet the proposed schedule for completion of the Stage 2 recommendations,
Arnold proposed the following milestones for the remaining meetings:
March meeting:
- Agree on framework we will use to discuss various scenarios.
- Agree on the scenarios we want the TWG to conduct analysis (further
analysis) on
- Agree on the FACA schedule and process for discussing the scenarios.
April meeting:
- Hear results of swat runs on selected scenarios identified in March
- Decide on which scenarios the FACA will tweak and pursue
- Identify questions for TWG
- Discuss one-text outline for Stage 2 recommendations (developed by
a subgroup of FACA members before the April meeting)
June meetings:
- Hear results of TWG analysis, negotiate one-text
- Finalize agreement
July meeting:
- Get ratification from various organizations - sign agreement
During this discussion, FACA members requested updates on chloroform,
EPA's health risk analysis, and the Dr. Waller and other reproductive
and developmental health research.
Stage 1 Baseline (ICR and Non-ICR): TWG Presentation
Mike McGuire, MEC and Stig Regli, EPA, presented the Characterization
of Technology Shifts and DBP Occurrence for Large Systems (ICR) [Attachment
III.a] and for small and medium, non-ICR, systems [Attachment III.b] developed
by the Technical Work Group.
McGuire began by presenting large ICR (surface water) systems and large
groundwater systems. These systems serve approximately half of the US
population. McGuire asked that FACA member concentrate on how the data
is presented, instead of the content of the data itself. The TWG will
be presenting a large amount of data in the coming meetings that FACA
members will have to understand and digest. The TWG is asking for feedback
from the FACA on what is the best format for the data? The amount of data
is overwhelming, it will be the job of the TWG to present analysis and
information that is useful to the FACA.
The TWG believes that the Stage 1 baseline is adequately described for
technology selection and DBP levels. Other polling methods appear to support
SWAT predictions. The Stage 1 baseline predictions can now be compared
with surface water and groundwater baselines.
In response to a question from a FACA member on the distribution of surface
water and ground water systems across states, Regli explained that there
are scientific data from 8 to 10 states for DBP occurrence versus TOC
occurrence from the 1980s, these include precursor occurrence data.
ICR/Large Surface Water Systems Stage 1 Baseline
The Stage 1 baseline compliance forecast for ICR systems (surface water
systems serving over 100,000 people) was estimated using four methods:
utility poll, least cost Delphi poll, best professional judgement Delphi
poll, and SWAT model prediction. For each of the methods McGuire described
the distribution of utilities across a list of ending technologies. Delphi
polls were conducted asking experts what utilities will have to do to
comply with the Stage 1 rule and recommendations for each system to comply.
A FACA member noted that process described by McGuire is really a "survey
of experts" and not a formal Delphi process. McGuire stated that the SWAT
tool is an analytical model based on ICR data. It can analyze large amounts
of data quickly. The TWG has endorsed the SWAT model and anticipates that
it will be the primary method of analyzing various Stage 2 scenarios for
large systems.
McGuire presented a comparison of technology shifts from different forecasting
methods. Any difference between the methods should be viewed as the range
of anticipated technology shifts. The final large surface water Stage
1 baseline ending technologies is included as Slide 20 [Attachment III].
These values will be used to compare with Stage 2 scenarios and to determine
cost estimates. McGuire also presented cost estimates for compliance with
Stage 1 and baseline TTHM, HAA5, and chlorite levels. The major shift
in HAA5s will be at high levels. Stage 1 Bromate levels are not yet available.
TWG has estimated that utilities will aim for over compliance for Stage
1 and set levels for 80% of the MCL. There is a mix of attitudes within
the industry on how to respond to the Stage 1 Rule, that will be in effect
(January 2001), and the anticipated Stage 2 rules. In developing estimates
the TWG has assumed that utilities will choose the least-cost option.
Though true maximum concentrations are not known, the TWG has a high degree
of confidence in the SWAT forecasts. SWAT calculations are designed to
determine a national estimate and should not be used for individual plant
predictions.
Non-ICR Systems Stage 1 Baseline
Stig Regli, EPA, presented the Stage 1 baseline estimates for non-ICR
surface water systems, medium sized systems (serving 10,000-100,000) were
assumed to have the same baseline as large systems (serving greater than
100,000) because they have similar source water quality and the same technology
decision tree. In other words, the distribution of technologies among
medium sized systems is assumed to be the same as for large sized systems
following the implementation of Stage 1.
Systems serving less than 10,000 people have a different compliance forecast
than for medium and large systems. Smaller systems have source water quality
and significant economies of scale considering technology choices for
meeting Stage 1 [Attachment III.b (slide 8)] illustrating technology compliance
forecast for small systems using surface water. Most noteworthy for small
systems using surface water is:
a) their very substantial shift to use of chloramines (about a 50 percent
shift away from chlorine) and
b) their substantial reduction in DBP exposure illustrated in the graph
[Attachment III.b., slide 9] for TTHM occurrence before and after Stage
1.
Large Groundwater Systems Stage 1 Baseline
McGuire presented Stage 1 baseline estimates for large groundwater systems
(serving greater than 100,000 people) including cost, TTHM and HAA5 estimates
[Attachment III.a (Slide 36)]. SWAT cannot be used for ground water, so
estimates depend on a survey of experts. Large groundwater systems serve
approximately 8 percent of the US population.
The TWG estimated technology selection for non-complying ICR groundwater
plants based on two Delphi polls. One poll asked experts to predict technology
shifts based on their best professional judgement, the second poll asked
experts to choose the least cost option. McGuire presented the final Stage
1 Baseline technologies and technology cost levels for large groundwater
systems. McGuire also presented Stage 1 baseline estimates for TTHM and
HAA5.
Non-ICR Groundwater Systems Stage 1 Baseline
Regli presented the predicted Stage 1 baseline for non-ICR groundwater
systems [III.b. slides 10-12]. Because of similarities in source water
quality and little difference of economies of scale the non-ICR baseline
can be expected to be similar for that of the large groundwater systems.
Large groundwater systems are assumed to be many small groundwater systems
because of the many wells needing separate treatment within each large
system.
Microbial Framework for Filtered Systems
Stig Regli, EPA, presented the preliminary microbial tool box of scenarios
based on FACA questions and potential framework for filtered systems [Attachment
IV.a].
The TWG has divided the FACA's microbial pathogen questions discussed
at the January FACA meeting into three categories:
1. Source water screening. The TWG is working on a microbial
index, identifying pathogen indicators, and identifying other watershed
characteristics. Identification of reliable indicators or other characterization
methods would support options that focus on systems with potentially higher
risks.
2. Source water monitoring. The TWG
is addressing four specific monitoring questions from the FACA. Source
water monitoring is feasible, though finished water monitoring with
present methods is not. FACA members asked for the following additional
analyses:
- Sensitivity analysis to define our capability to characterize occurrence
- including occurrence during peak events and overall mean concentrations.
- Since filtered systems have a substantial barrier, defining the
effects that peak occurrence in source water has on finished water
occurrence is a challenge. To what level do peak concentrations in
source water translate into finished waters peaks? AWWARF is currently
studying peak monitoring. The effects of higher turbidity are not
understood. There may be increased removal when turbidity is high
due to more particle interactions occuring. FACA members asked that
issues discussed by the TWG regarding filter performance be summarized
for FACA members.
- AWWARF is conducting a study, due for completion this summer, on
the variance in Crypto occurrence. Analysis of the data will
not be complete until early 2001. Measuring variance in Crypto
occurrence based on 12 months of data is a problem due to variation
between years. 12 months studied may be an unusual year.
4. Potential corrective actions. A list of "tools"
in three categories have been identified by the TWG that can reduce
exposure to Crypto: pretreatment/watershed (lower influent
concentrations), operational/reliability (enhance removal), and advanced
treatment (enhance removal or inactivation). The TWG is identifying
a range of tools and cost implications in the toolbox in each category
and definitions and capacities of each tool. Quantifying the reduction
in concentration, or credit, to assign specific controls is difficult.
In response to a question, Regli explained that the TWG is developing
a map for estimating inactivation by ultraviolet (UV) technology. UV is
encouraging, however, the practicality of full scale commercial implementation
of UV is still unclear to some TWG members.
- A FACA member requested that the TWG present to the FACA the TWG's
analysis of the viability of using UV in drinking water, including any
concerns individual TWG members might have.
- A FACA member requested further development of source water protection
options, how to deal with distribution systems, and finished water reservoirs.
EPA distributed a memorandum from EPA Assistant Administrator Chuck
Fox on examination and recommendations for EPA programs on waterborne
microbial disease [Attachment IV.b]. The memorandum is an effort to
link EPA water protection activities (including actions under the Clear
Water Act and Safe Drinking Water Act) to reduce microbial pathogen
occurrence.
Unit Costs for Various Technologies
Douglas Owen, Malcom Pirnie, presented overviews and cost estimates for
existing disinfection technology alternatives, options for reducing DBPs
with chlorine, and technologies for removing DBP precursors [Attachment
V]. These cost estimates are based on data from manufactures, plants,
pilot studies, and an industry data base. Owen provided cost information
and schematics on how alternative disinfectant, DBP reduction options
(with chlorine), and precursor removal technologies work.
Owen presented draft cost summaries for alternative disinfectants,
alternative disinfectants with free chlorine, and alternative precursor
removal technologies:
Alternative Disinfectants:
DRAFT Alternative
Disinfectants Cost Summary (Total Costs in $/k-gal)* |
|
0.1 |
1.0 |
10 |
100 |
UV |
0.47 |
0.13 |
0.07 |
0.05 |
ClO2 |
1.04 |
0.26 |
0.08 |
0.04 |
O3 (1-log Crypto) |
3.14 |
0.65 |
0.21 |
0.11 |
O3 (2-log Crypto) |
4.10 |
0.88 |
0.27 |
0.13 |
MF/UF (low) |
4.04 |
1.28 |
0.66 |
0.50 |
MF/UF (high) |
5.13 |
2.17 |
0.86 |
0.57 |
*Preliminary DRAFT: For FACA discussion only
In addition, Owen made the following points:
- Chlorine dioxide (ClO2) is estimated to provide 1/2 log Crypto
inactivation.
- Ozone may be feasible, however, bromate formation may be an
issue. Estimated costs of ozone do not include operational changes to
avoid bromate problems. In response to a question from the FACA, Owen
explained that electrical power makes up 30-50% of operational costs
of ozone and so may be sensitive to changing electricity costs. In response
to a question, Owen explained that redundancy in systems allows for
one unit to be brought offline for service without compromising treatment.
- The engineering reliability of UV technology is an issue. UV
inactivation at the UV does for which the cost analysis was conducted
is estimated at 2 logs for oocysts and viruses. UV systems are modular
and have large economies of scale. Power consumption is 20-25% of operational
costs.
- Physical removal, through filtration, may be limited by mechanical
reliability issues. Micro and ultra filtration costs depend greatly
on the water quality, amount of reject water, the cost of water, and
the disposal method for backwash. These systems, plus a residual, could
act as complete water treatment system.
Alternatives with Free Chlorine:
DRAFT Alternatives with Free Chlorine
Cost Summary
(Total Costs in $/k-gal)* |
|
0.1 |
1.0 |
10 |
100 |
Move Chlorine Application Point |
0.092 |
0.09 |
0.046 |
0.0020 |
Switch to Chloramines |
0.168 |
0.02 |
0.007 |
0.0015 |
*Preliminary DRAFT: For FACA discussion only
- Moving point of chlorine application is a relatively low cost approach.
- Switching to chloramination is a common approach for meeting Stage
1 rules.
Alternative Precursor Removal Technologies:
DRAFT Alternative Precursor Removal
Technologies: Cost Summary
(Total Costs in $/k-gal)* |
|
0.1 |
1.0 |
10 |
100 |
Enhanced Coagulation |
0.11 |
0.08 |
0.033 |
0.031 |
Enhanced Softening |
0.52 |
0.26 |
0.10 |
0.055 |
GAC10 (60 ug/L THM target) |
4.20 |
1.47 |
0.53 |
0.24 |
GAC20 (20 ug/L THM target) |
4.92 |
2.78 |
0.79 |
0.55 |
NF with Direct discharge of Concentrate |
6.32 |
3.74 |
1.33 |
1.03 |
Int. Membranes (MF/UF - NF) |
10.36 |
5.02 |
1.99 |
1.53 |
*Preliminary DRAFT: For FACA discussion only
- Granular Activated Carbon Adsorption - costs are sensitive to quantity
of water applied and frequency of reactivation
A FACA member noted that an important consideration in cost is how technology
will change the footprint of the plant, and if technology changes are
associated with other changes at a plant.
Examples of Stage 2 Scenarios Developed by TWG
Mike McGuire presented example technology
shift selections and TTHM/HAA5 exposure outputs for two Stage 2 options
using SWAT [Attachment VI]. McGuire explained that the main purpose of
this presentation is to gain feedback on how the TWG should present the
data to the FACA - these option predictions should not be used as a basis
for decisionmaking. Stage 2 predictions are based on SWAT only (not the
four estimates used for Stage 1).
McGuire reminded FACA members that compliance will be different then
the SWAT output. SWAT has the option of including or excluding the use
of UV. For this presentation the TWG developed SWAT (large surface water
system) predictions for two options:
- 40 TTHM and 30 HAA5 (40/30) as a running annual average (RAA). This
example also assumed 1-log Crypto inactivation requirement
and excluded UV.
- 80 TTHM and 60 HAA5 (80/60 as a single highest (SH) allowed value.
This example also assumed 1-log Crypto inactivation requirement
and included UV.
For these two example runs the McGuire presented new technology selections,
new technology cost levels, ending technologies, and ending technology
cost levels. SWAT also estimated cumulative probability plots of TTHMs
and HAA5s for running annual averages and cumulative probability plots
of TTHMs and HAA5s for single highest values. In addition to the presented
materials McGuire made the following points:
- 1-log Crypto removal is an important constraint - causes
a large shift in technology, especially to UV when UV is allowed as
a technology option in the model. When UV is not allowed, the primary
shift is to ozone in plants with relatively low bromide levels.
- In response to a question McGuire noted that the inactivation requirement
can also be met by physical removal (e.g., microfiltration or nanofiltration).
- Largest decreases in DBPs (TTHM and HAA5) occur in those systems with
the highest levels of DBPs.
In conclusion, McGuire noted that the option conditions chosen (e.g.
Crypto inaction levels and availability of UV) have a profound
impact on the Stage 2 technology predictions. DBPs can be shown to dramatically
decrease after the application of advanced, relatively costly technology.
A very large number of SWAT runs (160 or more) may need to be examined.
Examples of Stage 2 Impacts To Non-ICR Systems
Waiting for additional comments on this section.
Stig Regli presented example estimates of Stage 2 impacts to non-ICR
systems [Attachment VII]. Regli presented predicted technology changes
for each system type and size for a range of six example regulatory endpoints.
Examples were developed for four systems categories:
- Medium surface water systems: extrapolated from ICR SWAT Stage 2 estimates
- Small surface water systems: survey of expert
- Medium ground water systems: extrapolated from ICR GW estimates
- Small ground water systems: extrapolated from ICR GW estimates
Under many of the scenarios, utilities that made changes to meet Stage
1 rules will meet the Stage 2 requirements. There is now decent small
systems impact data, including data on why systems are choosing to make
technology shifts for Stage 1.
- In response to a question from a FACA member Regli noted that UV is
less expensive than ozone and is a frequent choice for Stage 1 compliance
when UV is included as a technology option.
Framework and Examples To Discuss Stage 2 Scenarios
Ephraim King, EPA, presented a suggested approach for thinking through
data and providing direction to the TWG [Attachment VIII]. King explained
that the data in this presentation are examples of data that could be
generated by the TWG - not actual data. The TWG can develop methodology
for identifying systems with different levels of pathogen exposure and
identify how systems can lower pathogen exposures. The TWG can characterize
impacts of rule options (Stage 2 DBP and LT2ESWTR) including; percent
of systems affected, technology shifts, costs, and changes in exposure.
It is not possible to accurately estimate changes in risk.
King recommended that the FACA develop rule options for the TWG to evaluate
that consider microbial (LT2ESWTR) and DBP (DBP2R) simultaneously. Impacts
of each rule can also be evaluated separately by setting no action for
either rule.
Suggested Framework for FACA Discussion |
|
Stage 2 DBP Level of Stringency |
|
option a |
option b |
option c |
option d |
LT2ESWTR
Level of stringency |
option a |
|
|
|
option b |
|
|
|
option c |
|
|
|
option d |
|
|
King also presented example summaries of SWAT preliminary screening runs:
Example M-DBP Scenario Matrix: Sample only- Draft applies
only to filtered systems
DBP rule options (stringency increases) |
LT2 ESWTR options (string-ency
increas-es)
|
|
TTHM/HAA5 80/60
annual average @ max
Bromate 10 |
TTHM/HAA5 80/60
quarterly average @ max
Bromate 10 |
TTHM/HAA5 80/60
single max
Bromate 10 |
40/30 annual average
Bromate 5 |
|
Framework Option 1(systems with mean Crypto.conc
>1/10 L provide additional Crypto control)
|
% systems affected
Simple characterization of technology shift
DBP shift
Relative costs |
% systems affected
Simple characterization of technology shift
DBP shift
Relative costs |
% systems affected
Simple characterization of technology shift
DBP shift
Relative costs |
% systems affected
Simple characterization of technology shift
DBP shift
Relative costs |
|
Framework Option 2 (systems with mean Crypto conc
> 1/100 L provide additional
Crypto control) |
As above |
As above |
As above |
As above |
|
1 log inactivation for all systems |
As above |
As above |
As above |
As above |
Initial SWAT screening runs of regulatory options have been performed:
- TTHM/HAA5 number at 80/60, 70/50, 60/40, and 40/30.
- Determinations of compliance at current, maximum annual average, or
single maximum at 120/100, 110/90, 100/80, and 90/70
- Bromate at 10 ppb or 5 ppb
- Crypto inactivation at 0 log (assumes 2 log removal) or additional
0.5 and 1 log
- UV on or off
- Over 200 regulatory options screened.
Changes from Stage 1 Baseline for Stage 2 Scenarios
- Draft applies only to filtered systems |
|
% Shift in Technology Cost Categories For SW Systems
>100,000 |
|
|
|
|
|
|
DBPR Scenario |
<25c/1K gal |
25-50c/1K gal |
$1-3/1K gal |
Total % Shift |
% Chloramine shift |
does not include LT2ESWTR Option |
|
|
|
|
|
|
|
|
|
|
|
Stage 1 Baseline (w/ HAA6) |
0 |
1 |
0 |
1 |
0 |
120/100 Single Max |
0 |
2 |
0 |
2 |
5 |
80/60 Annual Average of the Max |
0 |
4 |
0 |
4 |
1 |
110/90 Single Max |
0 |
5 |
0 |
6 |
5 |
80/60 75%ile of the Max |
2 |
4 |
0 |
6 |
7 |
100/80 Single Max |
4 |
7 |
0 |
11 |
10 |
80/60 90%ile of the Max |
3 |
10 |
0 |
13 |
6 |
80/60 Quarterly Average of the Max |
4 |
10 |
0 |
14 |
12 |
90/70 Single Max |
6 |
10 |
0 |
17 |
13 |
80/60 Single Max |
6 |
18 |
0 |
24 |
13 |
70/50 Single Max |
5 |
24 |
1 |
31 |
17 |
40/30 RAA |
12 |
25 |
0 |
37 |
15 |
40/30 Annual Average of the Max |
6 |
30 |
1 |
38 |
17 |
60/40 Single Max |
7 |
32 |
2 |
41 |
16 |
40/30 75%ile of the Max |
8 |
35 |
2 |
44 |
18 |
40/30 90%ile of the Max |
7 |
38 |
2 |
47 |
17 |
40/30 Quarterly Average of the Max |
8 |
40 |
3 |
51 |
21 |
40/30 Single Max |
6 |
47 |
5 |
59 |
17 |
|
|
|
|
|
|
|
Stage 1 Baseline Ending Technologies |
Stage 1 DBPR (80/60/10) |
Ozone or Chlorine Dioxide |
MF/UF or GAC 10/20 |
Nanofiltration |
Conv/No Change |
% Chloramine |
|
|
|
|
|
|
Stage 1 Baseline |
17 |
4 |
0 |
78 |
53 |
DRAFT SWAT Preliminary Screening
Runs: Sample Only applies only to filtered systems
Microbial
and Technology Conditions |
Regulatory
Option |
Total Fraction
CLM |
Fraction of
Advanced Technology |
TTHM, ug/L |
HAA5, ug/L |
BrO3, ug/L |
|
|
|
|
90%
Annual Avg, DS Avg |
90% Quarterly
Avg, DS Max |
90% Annual
Avg, DS Avg |
90% Quarterly
Avg, DS Max |
90% Annual
Avg |
1.0-log Incremental
Crypto Inactivation |
80/60 RAA |
10 |
99 |
0 |
3 |
49 |
63 |
38 |
|
40/30 RAA |
25 |
52 |
0 |
2 |
39 |
49 |
29 |
|
80/60 Locational Quarterly
Avg |
11 |
40 |
0 |
2 |
55 |
66 |
38 |
|
40/30 Locational Quarterly
Avg |
22 |
99 |
0 |
5 |
37 |
46 |
29 |
|
120/100 Single Highest |
9 |
99 |
0 |
5 |
46 |
60 |
37 |
|
80/60 Single Highest |
24 |
40 |
0 |
4 |
40 |
49 |
30 |
|
40/30 Single Highest |
12 |
27 |
0 |
3 |
55 |
65 |
38 |
King presented the estimated range of technology costs for the following
scenarios for all systems and broken down by large, medium and small systems:
- 40/30 running annual average, 1 log removal, with and without UV
- 80/60 single maximum, 1 log, with and without UV
Scenarios for TWG Analysis and FACA Deliberation
FACA members met in caucus and cross-caucus meetings to develop a set
of scenarios for TWG analysis. The TWG will analyze the following scenarios
for presentation at the April FACA meeting:
Regulatory Option Matrix From March 30, 2000 FACA Meeting (corrected
by TWG)
DBPs: |
120/90
Single Highest |
80/60
Locational Running Annual Ave |
80/60
Annual Ave of the Maximum |
80/60
Single Highest |
40/30
Single Highest |
Microbial: |
|
|
|
|
|
0 log Crypto removal (UV off) |
x |
x |
x |
x |
x |
0.5 log Crypto removal |
xx
(UV on/off)
(Bromate=10) |
xx
(UV on/off)
(Bromate=10) |
xx
(UV on/off)
(Bromate=10) |
xxxx
(UV on/off) (Bromate=5/10) |
xx
(UV on/off)
(Bromate=10) |
Sort Only 20%
2.0 log Crypto removal-(UV on) |
|
|
|
|
|
2.0 log Crypto removal |
xx
(UV on/off)
(Bromate=10) |
xx
(UV on/off)
(Bromate=10) |
xx
(UV on/off)
(Bromate=10) |
xxxx
(UV on/off) (Bromate=5/10) |
xx
(UV on/off)
(Bromate=10) |
|
|
+Small Systems & National Costs |
|
+Small Systems & National Costs |
|
In addition to the scenarios, FACA members requested that the following
information be provided or analyses be performed:
- Work on Microbial Framework (toolbox) for source waters: monitoring
feasibility & control enhancement measures.
- Monster SWAT Run: GAC 10 (1986 SDWA Amendment definition); prepare
a cumulative probability distribution of TTHM and HAA5; set MCLs for
the DBP levels at the 90th percentiles; perform Smart SWAT
runs based on these MCLs.
- Distribution System Water Quality Framework: reliability issues (EPA
has some information)
- Screening SWAT Runs: Sort 160 screening SWAT runs by significant technology
shifts (UV is a significant tech shift), national costs of SWAT utilities,
and DBP exposure (is there a "knee in the curve"?)
- For Stage 1 Baseline SWAT run (80/60 Running Annual Average), sort
monthly DBP predictions for all 273 plants by increasing levels of TTHM
and HAA5 and determine how many plants are over 120/90 as single highest
value the following number of times (1, 2, 3, etc.).
- Next, for Stage 1 Baseline SWAT run (80/60 Running Annual Average),
sort monthly DBP predictions for all 273 plants by increasing levels
of TTHM and HAA5 and determine which plants ever exceed 120/90 as single
highest value; then go to the SWAT run for 120/90 and identify what
those plants had to do to comply with 120/90. Present technology shifts
meeting 120/90 single highest value under these conditions (this may
be an example of a composite regulatory option combining RAA and SH).
The following additional points were made during FACA deliberations:
- In response to a question from the FACA, EPA agreed to provide data
on water quality criteria for microbial pathogens and data on tools
for regulating upstream users. The FACA can make recommendations regarding
a source water protection approach. FACA members requested information
on what streams are designated drinking water sources and data on where
utilities are versus water quality characteristics. However, implementing
upstream rules will be more difficult because states will have primary
implementation responsibility.
- The traditional risk calculation and cost and benefit analysis of
the Stage 2 MDBP options will be performed by EPA, however, EPA anticipates
that the FACA's best professional judgement will be the driver in the
regulations because of the high level of uncertainty.
- In the past, EPA has defined affordability as a cost increase of $500
per year per household for all regulations.
Public Comment
Sidney Ellner, Ultratech, addressed the FACA on UV technologies. UV technologies
have the experience to handle large systems and tools for monitoring effectiveness
of UV exist. UV cannot overdose water and leaves no detectable residual
in water. Bioassays and electronics are used to test effectiveness of
system. UV systems are highly reliable, and typically consist of a fluorescent
lamp (without phosphorus) and ballast. There are percentage failure data
for systems. In response to a question from the FACA, Ellner explained
that mercury is used in the lamps, however there is less mercury in a
UV lamp than in a normal fluorescent lamp. UV lamps are housed in a quartz
jacket that separates the lamp from water and allows maintenance of lamps
without interfering with water flow. There is no significant history of
breakage of lamps. Possible concerns of irradiation of water by the public
have not been addressed. However, among other uses, Johnson and Johnson
uses UV to disinfect baby products. These uses have not raised public
fears.
Next Steps
FACA members discussed the following next steps:
1. TWG will perform analysis of the scenarios requested for the April
meeting.
2. FACA subgroup will meet to develop one-text agreement draft.
3. Anticipated April FACA agenda items:
- TWG Report
- Discuss one-text FACA perspective on health risks (reproductive
& developmental /cancer, DBP/micro).
- Caucus Time
4. June FACA meetings - possible agenda items:
- UV safety and reliability
- Reproductive and developmental health effects data update
- Status report on chloroform
Adjourn
1. The MWRA is a member organization of a party
represented on the FACA. Defense attorneys representing MWRA used materials
discussed by EPA staff during informal telephone conversation and at
a TWG meeting in litigation with US EPA. The Attorney represented that
the materials as EPA's position. The M/DBP groundrules state that: "Specific
offers, positions, or statements made during the discussions may not
be used by other parties for any purpose outside the discussions or
as a basis for future or in current litigation". (Section 6.a.
page 3).
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