The Stage 2 D/DBPR and LT2ESWTR--Where are We Going
J. Alan Roberson, P.E.Director of Regulatory Affairs
AWWA-Washington, DC
Outline
Overview of the M/DBP Cluster Overview of IESWTR and Stage 1 D/DBPR Preliminary ICR Data Analysis Where the LT2ESWTR and Stage 2
D/DBPR May Be Going
Microbial/Disinfection By-Products (M/DBP) Cluster
Balancing of acute microbial risks with chronic chemical risk a unique regulatory challenge
EPA used negotiative processes instead of traditional proposal and public comment ‘92 & ‘93 negotiated rulemaking (Reg-Neg) led to ‘94
proposals for ICR, Stage 1 D/DBPR , & IESWTR ICR data would be used for selection of IESWTR option
ICR delayed due to multiple problems ICR monitoring started in July, 1997 instead of October, 1994
Led to ‘97 Federal Advisory Committee (FACA)
1997 Federal Advisory Committee (FACA) Process
Looked at components of ‘94 proposals What can we use to meet statutory deadlines?
FACA met through March-July, 1997 Agreement in Principle signed in July, 1997
Notice of Data Availability published in Federal Register on March 31, 1998 IESWTR focused on new turbidity standards
Profiling/benchmarking provisions Minor changes to Stage 1 D/DBPR
The First Regulations in the M/DBP Cluster
Stage 1 D/DBPR & IESWTR published in the Federal Register on Dec. 16, 1998 New MCLs and treatment techniques Optimizing existing treatment rather than major
shifts to alternative technologies Costs not insignificant--$1 Billion/year Compliance in 2001 & 2003
LT1ESWTR for systems <10,000 people Final in 2000 and compliance in 2003
Stage 1 D/DBPR
Lowers existing MCL for TTHM from 0.10 mg/l (100 ug/l) to 0.080 mg/l (80 ug/l) Applies to all systems (except for transients)
Phased compliance for small systems Establishes new MCLs
HAA5--0.060 mg/l (60 ug/l) MCAA, DCAA, TCAA, MBAA, DBAA
Chlorite--1.0 mg/l Bromate--0.010 mg/l (10 ug/l)
Stage 1 D/DBPR (cont.)
Establishes Maximum Residual Disinfectants Levels (MRDLs) for common disinfectants Chlorine & chloramine--4.0 mg/l (as Cl2) Chlorine Dioxide--0.8 mg/l (as ClO2)
Daily monitoring for chlorine dioxide & transients MRDLs can be exceeded for short periods
Enhanced coagulation and softening treatment technique for TOC removal Step 1 matrix & Step 2 process (with “outs”)
IESWTR
Surface water systems serving >10,000 people 2 logs Cryptosporidium removal credit for
conventional treatment Lowered combined filter turbidity
From <0.5 NTU to <0.3 NTU 95% of the time From <5 NTU to <1 NTU as a maximum
Monitor treatment processes carefully Compliance still based on 4-hr. intervals
IESWTR (cont.) Individual filter turbidimeters
Readings every fifteen minutes Exceptions reported to state when:
>1.0 NTU for any 2 15-min. readings or >0.5 NTU for any 2 readings after 1st 4 hours
Develop filter profile within 7 days Self-assessment for >1.0 NTU for 2 15-min. readings at
any time in 3 consecutive months Comprehensive Performance Evaluation for >1.0 NTU
in 2 consecutive months
IESWTR (cont.)
Profiling & Benchmarking TTHM >0.064 mg/l or HAA5>0.048 mg/l
Develop profile-daily inactivation for one year based on daily measurements of operational data
Calculate benchmark & consult with State Lowest monthly average inactivation
Cover new finished water reservoirs Sanitary survey requirements
Information Collection Rule
DBP and microbial monitoring data to be used for the Stage 2 D/DBPR & LT2ESWTR
18 months of data from the systems serving >100,000 people--296 utilities--501 plants July, 1997 to December, 1998 Data is currently being analyzed
A lot more work than initially thought Bench- and pilot-scale treatment studies for systems
with high levels of DBP precursors
ICR Data Analysis Tools
ICRFED--the very large Federal database for all monitoring & engineering data
Auxiliary databases developed for more relevant data (Access-based) Available on CD from EPA
Stage 1 baseline & Stage 2 options Surface Water Analytical Tool (SWAT)
Results extrapolated for medium & small systems Expert panel for large groundwater systems
Aux 2CT &
Disinfectant Decay Aux 3
Enhanced Coagulation
Aux 4Sludge
Production . Aux 5
Washwater Return
Aux 6Distribution
System DBPs
Utility and Plant Level Data
Sampling Results Data
Treatment Operation Data
Aux 1 - Primary Auxiliary Database
QueryTool
Aux 8Model
Interface/ Database
Auxiliary Database Relationships
Surface Water Analysis Tool Data Process Overview
Aux1
Aux8
SWAT/ Model
Model Inputs
Selection Criteria
Graphical User Interface (GUI)
Model Outputs
Final Large Surface Water Stage 1 Baseline Technology Cost Levels
79%
19%
1% 0% 1%0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
ConventionalTechnologies
Advanced Disinfect GAC10 GAC20 Membranes
Frac
tion
of P
lant
s, %
Historical Comparison of TTHM Cumul. Freq. Distributions
AWWARF Survey 1984-86 727 utilities
NOMS--1976-77 450 utilities
NORS--1975 490 utilities
ICR--three quarters of data 469 plants; 1002 quarterly averages
Stage 1 Baseline TTHM Levels
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 20 40 60 80 100 120 140
Distribution System Annual Average TTHM, ug/L
Cum
ulat
ive
Prob
abili
ty, %
SWAT Stage 1 Baseline ICR Observed
Change in National TTHM Levels by Stage 1:
ICR Observed Median 43.5 ug/LStage 1 Baseline Median 35.2 ug/L Delta: 8.3 ug/L
Stage 1 Baseline HAA5 Levels
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 20 40 60 80 100 120 140
Distribution System Annual Average HAA5, ug/L
Cum
ulat
ive
Prob
abili
ty, %
SWAT Stage 1Baseline ICR Observed
Change in National HAA5 Levels by Stage 1:
ICR Observed Median 25.7 ug/LStage 1 Baseline Median 23.7 ug/L Delta: 2.0 ug/L
TTHM v. HAA5 Plot--Stage 1 Baseline--Running Annual Averages
0
10
20
30
40
50
60
70
80
0 10 20 30 40 50 60
Annual Average HAA5, ug/L
Ann
ual A
vera
ge T
THM
, ug/
L
TTHM v. HAA5 Plot--Stage 1 Baseline--Single Highest
0
50
100
150
200
250
300
350
0 50 100 150 200 250 300
Single Highest HAA5, ug/L
Sing
le H
ighe
st T
THM
, ug/
L
TTHM v. HAA5--ICR Maximum Values Based on 4 Quarters
Microbial Monitoring
Source water monitoring Giardia, Cryptosporidium, viruses, & coliforms
Virus monitoring “out” Finished water monitoring
Giardia & Cryptosporidium monitoring based on triggers in source water monitoring
Not many plants monitored finished water Handful of detects in finished water
Microbial Monitoring (cont.)
Cryptosporidium results (total) 93% non-detects
Higher detections in flowing streams versus reservoirs Supplemental survey results--higher detectsions
Giardia results (total) 82 % non-detects Similar higher detections in flowing streams
Virus results--77% non-detects
Cryptosporidium ResultsPercentage Non-Detects--18 Months ICR Data
Total Amor +Internal
Internal
SW 93% 95% 98%
FS 82% 92% 96%
RL 96% 97% 99%
Stage 2 D/DBPR & LT2ESWTR
Part of the ‘92-’93 Reg-Neg agreement EPA committed to meeting their deadlines
How far do we need to go beyond the Stage 1 D/DBPR & IESWTR?
Negotiations April, 1999-July, 2000 New health effects data & ICR data will be a key
part of the negotiations Proposal in early 2001 Final in May, 2002
The Possible Future for the Stage 2 D/DBPR & LT2ESWTR
Major changes to the Stage 1 rules Single Maximums Cryptosporidium inactivation requirement
Inactivation based on additional monitoring? 1 log additional for systems on flowing streams
Minor changes to the Stage 1 rules Shaving peak DBP levels Distribution systems??
States requirement for cross-connection controls
Potential Stage 2 D/DBPR & LT2ESWTR Options
DBP options 80/60 annual average of the maximum
Similar to location running annual average Single max.--80/60 & 40/30 as MCLs and 120/90 as
an Action Level (combinations?) Bromate at either 10 ppb or 5 ppb
Cryptosporidium inactivation 0, 0.5 log, and 2.0 log requirement Ultraviolet (UV) light treatment on and off
The Revised Matrix--41 SWAT Runs
DBPs:
Microbial:
120/90Single
Highest
80/60Running
Annual Ave
80/60Annual Ave
of theMaximum
80/60Single Highest
40/30Single
Highest
0 log Cryptoremoval (UV off)
x x x x x
0.5 log Cryptoremoval
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 Cryptoremoval
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)
2.0 log Cryptoremoval
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)
+SmallSystems &National
Costs
+Small Systems& National
Costs
Comparison of RAA, LRAA and AAM from ICR TTHM Data--Cl2 Plants
THM4 OPTIONS: CL2 PLANTS
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 50 100 150
THM4 (ug/L)
RAA LRAA AAM QAVG QMAX
Comparison of RAA, LRAA and AAM from ICR TTHM Data--CLM Plants
THM4 OPTIONS: CLM PLANTS
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 50 100 150
THM4 (ug/L)
RAA LRAA AAM QAVG QMAX
RAA EquivalenciesBased on ICR plant data
80
6067
4554
4147
35
01020304050607080
RAA LRAA orAAM
QTR. AVG. SINGLEMAX.
TTHMHAA5
80/60 RAA EquivalenciesBased on ICR plant data
80
60
95
80
122
100
138120
0
20
40
60
80
100
120
140
RAA LRAA QTR. AVG. SINGLEMAX.
TTHMHAA5
Elements of Potential Microbial Framework
Treatment Characterization Characterize source water
Determine whether additional Cryptosporidium monitoring is necessary
Monitoring criteria for estimating mean Cryptosporidium concentrations in source water
Criteria for classifying potential exposure Using mean Cryptosporidium concentration and treatment
characterization for plant Criteria for mitigating potential exposure
Based on watershed and/or treatment control measures
Treatment Characterization
Characterize existing treatment Compare to toolbox Determine if adequate and whether further
action is necessary. (see toolbox)
Characterize Source Water - Determine if Cryptosporidium monitoring is needed
Use one or more of following: fecal coliform, E.coli , Total coliform, turbidity, as indicator(s) of challenged watershed, and/or watershed characteristics (a watershed index) If indicator(s) (possibly a mean value) is below a
critical level, system would be below Crypto occurrence level of concern
Acceptable misclassification rates a major issue
Vulnerability Index
Supplemental Surveys, 9 months, n>=9E. coli (55 plants)
Crypto >10 >50 >100 >200bin Exceed Not Exceed Not Exceed Not Exceed Not0-10 20 27 14 33 6 41 5 42
>10, <=100 6 2 4 4 2 6 1 7>100 0 0 0 0 0 0 0 0
ICR, 18 months, n>=9E. coli (192 plants)
Crypto >10 >50 >100 >200bin Exceed Not Exceed Not Exceed Not Exceed Not0-10 78 84 39 123 29 133 17 145
>10, <=100 25 1 19 7 17 9 12 14>100 3 1 3 1 3 1 3 1
Protective Correct Incorrect of Concern
Characterize Source Water - Monitoring Criteria for Estimating Means
Suggested conditions: 24 monthly samples (2 years)), at least 10L/sample, 40% mean recovery, 50% CV, approximately $500./sample)
Concerns: high costs (utilities and states), method is not approved, interpretation of results, high burden on small systems, does not measure infective Crypto, not necessarily capturing peak events
Benefits: most direct way of determining relative levels of Crypto in the source water
Characterize Source Water - Monitoring Criteria for Estimating Means
Plants that must monitor would monitor monthly for Cryptosporidium in source water at intake of each plant Method 1623 (or equivalent) by approved labs
At the end of 2 years, systems would calculate option 1: mean value option 2: highest running annual mean
Systems would use mean concentration of each plant to classify potential exposure
Classifying Potential Categories Distinguish relative amounts of Cryptosporidium in source water
Plant Highest Running Action to Reduce Category Annual Mean Exposure
D >1.0/L “Toolbox ”
C >0.1/L to < 1.0/L “Toolbox”
B > 0.01/L to < 0.1/L No Action/“Toolbox ”
A < 0.01/L No Action
Treatment Toolbox Options
OPTION Crypto Category Shift
Lower Finished Water NTU to Half IESWTR Levels XPeer Review Program XRoughing Filter XPre-settling Basin No Coagulant Addition Coagulant Addition
XX
Inactivation X> 30 Day Off Stream Storage X> 60 Day Off Stream Storage XWatershed ProtectionDemonstration of Performance
Challenges = (1) assigning category shift values and
(2) implementation transaction costs for utilities and States
Total Annualized Costs-- Medium & Large SW Systems
Total Annual Costs, $Millions/YrDBP Compliance Levels
0 Log Crypto UV Off $ 70 $ - $ 30 $ 320 $ 1,480 UV On $ 250 $ 150 $ 180 $ 630 $ 1,540 UV Off $ 510 $ 420 $ 440 $ 850 $ 1,770 UV On $ 270 $ 180 $ 230 $ 680 $ 1,900 UV Off $ 500 $ 420 $ 470 $ 860 $ 2,050 UV On $ 1,090 $ 910 $ 990 $ 2,100 $ 3,580 UV Off $ 2,240 $ 2,120 $ 2,210 $ 3,040 $ 4,340
Note: Bromate MCL = 10 ug/L for all of these scenarios
0.5 Log Crypto
20% go to 2.0 log
2.0 Log Crypto
Inactivation40/30 Single
Highest
120/90 Single
Highest
80/60 RAA
80/60 AAM
80/60 Single
Highest
Capital Costs -- Medium & Large SW Systems
Total Capital Costs, $BillionsDBP Compliance Levels
0 Log Crypto UV Off 0.5 $0 0.3 2.3 11.6UV On 2.4 1.8 2.0 4.8 10.8UV Off 3.2 2.6 2.8 5.7 12.0UV On 2.0 1.3 1.7 4.6 13.8UV Off 3.3 2.7 3.1 5.7 14.6UV On 7.8 6.7 7.2 13.7 22.5UV Off 14.4 13.6 14.2 19.0 26.8
Note: Bromate MCL = 10 ug/L for all of these scenarios
40/30 Single Highest
120/90 Single
Highest
80/60 RAA
80/60 AAM
80/60 Single
Highest
0.5 Log Crypto
20% go to 2.0 log
2.0 Log Crypto
Inactivation
Household Costs -- Medium & Large SW Systems
Household Costs, $/HH/YrDBP Compliance Levels
0 Log Crypto UV Off 90 0 30 370 1,610UV On 210 90 120 650 1,770UV Off 470 350 370 890 2,060UV On 90 0 30 370 1,610UV Off 90 0 30 370 1,610UV On 1,390 1,150 1,260 2,760 4,760UV Off 2,880 2,720 2,840 3,980 5,770
Note: Bromate MCL = 10 ug/L for all of these scenarios
40/30 Single Highest
120/90 Single Highest 80/60 RAA 80/60 AAM 80/60 Single
Highest
0.5 Log Crypto
20% go to 2.0 log
2.0 Log Crypto
Inactivation
Conclusions
EPA is going to propose a rule in early 2001 FACA will have to scramble to complete their
negotiations by July, 2000 Most everyone has some concern about high
single DBP values Most everyone has some concern about
systems “vulnerable” to microbial contamination