Utility Water Act GroupG 

April 5: 2010 

Sieeiing!,\odit Cornmillei. 

Angeia %I. Gioi)iiis, 

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C. Richaiii i3uieh 

Rz~yhum L. iiuits 

Alan E. Gniiiha 

1.1. K. IMizk) Gicccoii 

L>ai id M, LLC 

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J<~ho G. Vaiei-i. fsq. 

Km) M. Wiie1:in 

Jiidsoii Whirc 

I;ll.f: YO.: 2~111?070??1 

-Mr. Ronald P. Jordan 

U. S. EPA 

Engineering & Analysis Division (4303T) 

Ariel Rios B~iilding 

1200 Pennsylvania Avenue, N.W. 

Washington, DC 20460 

UWAG Comments on EPA Draft Generic Sampling 

and Analysis Plan for Steam Electric Power Plan& 

Dear Ron: 

The Utility Water Act Group (UWAG) is pleased Lo submit comments on EPA's draft 

"Generic Sampling and Analysis Pian for Steam Electric Power Plants" (SAP). These comments 

reiterate many of the issues we raised with you during our meeting of March 1 I. We urge you to 

consider these comments and revise the SAP before beginning the sampling program. The 

changes we are recommending wili improve the accuracy, reliability, and representativeness of 

the overall data produced by the sampling program. 

A. EPA Should Sample at a Larger Kurnber of Facilities 

According to the SAP, EPA is planning to gather FGD wastewater samples at seven 

facilities. One of the chosen facilities -- Beiews Creek -- has already been sampled by EPA. 

Given that many facilities have added or are planning to add new FGD systems, a sample size of 

seven facilities is inadequate to provide a representative view of FGD wastewater treatment 

system performance or effluent quality. As we noted during our March 1 1 meeting, FGD 

wastewater composition, and FGD wastewater treatment system operations, vary widely. For 

example, hydra~~lic residence times within the systems can vary from 1 to 30 days. Dissolved 

concentrations of constituents within the systems vary slowly, over weeks or months, due to the 

oxidation state of the FGD system. The oxidation slate of the FGD system is a function of many 

factors, including, but not limited to, coal source, NOx control technologies, ESP and scrubber 

design and performance, chemical additives, raw water supply, and the recycling of FGD water 

back into the scrubber. While the cause-effect relationship between these factors and the 

oxidation siate of the FGD system is not yet clearly understood, the oxidation state of the FGD 

scrubber water is a major fileror (most likely the major factor) that controls the distribution of 

Hunton &Williams LLP .Counsel to UVJAC * 1900 K Street, N.W. Washington. D.C. 20006 
Mr. Ronald P. Jordan 

April 5, 2010 

Page 2 

constituents between the dissolved and solid phases. Thus, the selection of FGD systems to be 

sampled is critical for characterizing the range and variability of consticuellts in FGD wastewaier. 

Liinestone forced oxidation (LSFO) systems are coiltrolled well for SO2 reluoval. There 

is always excess oxygen present to oxidize sulfite/bisulfite. However, the oxidation state of 

LSFO systems are highly variable and somewhat unpredictable even for the same oxygen-tosulfur stoichioinetry and pH. This variability leads to variability in wastewater influent 

characteristics, which in turn affects wastewater treatment performance and effluent quality. 

Sampling only seven FGD systems sinipiy will not demonstrate the true variability of FGD 

systems across the steam electric industry. Therefore, we urge EPA to increase the number of 

FGD systeins sampled. In addition, EPA sho~rld measure oxidation-reduction potential (ORP) of 

the FGD absorber slurry during the sampling events. ORP is an indicator of the FGD's oxidation 

state. Most plants do not monitor ORP on a routine basis, and most ORP meters in water 

chemistry labs are not suitable for slurry measurement. If EPA is interested in collecting this 

information, an analytical method and an equipment list can be provided to EPA. 

Additional facilities to be sampled should include plants that are intermediate or cycling 

plants. These are plants that start up and shui down more frequently due to load demands. The 

frequency of start-ups and shut-downs can have a major impact on the performance of FGD 

wastewater treatment systems and the effluent quality. Aiso, EPA should sample more than one 

Facility burning Powder River Basin (PRB) coal. 

We understand that increasing the sample set raises budget concerns. However, this 

expenditure is necessary to provide appropriate dava to serve as the basis of the rulemaking. 

Also, as described below, UWAG recommends some changes to the SAP that will improve the 

accuracy and representativeness of the data* but will also decrease the cost of each sampling 

event. Those changes will result in a cost savings to EPA that could be used to fund sampling at 

a broader range of facilities. 

B. Four Days of Sampling Will Not Capture the Variability of Systems 

For each sampling site, EPA plans io collect four consecutive daily samples (SAP, 

p. 2-61, Collecting four consecutive daily samples is unnecessary because it does not capture the 

variability of the FGD systems. Because hydraulic residence times for FGD wastewater 

treatment systems range from one to 30 days, some of the systems EPA has selected for 

sampling have residence tirnes that are longer than four days. For example, WE Energies' 

Pleasant Prairie Power Plant has a hydraulic residence time of approximately 28 days. This 

residence time is about an order of magnitude longer than what is observed at a typical 

bituminous coal plant due to the low ieveis of sulfate and chloride in the PRB coal. Also, Duke's 
Mr. Ronald P. Jordan 

April 5,2010 

Page 3 

Belews Creek Station has a hydraulic residence time of 8 days. For FGD syste17z.s with I-esideielzc'e 

times thnt czre longer thurzfour days, unalyzingfour consecutive daily suwz/~les is essentially tize 

siirne us clnulyzing,fij~lr uliquots ofrhe sanze .scii7zple. Therefore, this approach will not provide 

any measure of system variability hr the selected facilities with residence times greater than four 

days.' 

Also, the performance of FGD wastewater treatment systems is known to be affected by 

climactic conditions. For instance, biological reactors often need special measures taken during 

cold months to prevent die-off of the reactor organisms. It has been well docunlented that the 

metabolism and reproductivity of bacteria are greatly affected by cold temperatures. The 

performance of FGD wastewater treatment systems is also affected by plant loading conditions 

tied to seasonal trends in power demand. A plant operating at 100% capacity during hot summer 

lnonths will have a different FGD wastewater composition compared to the same plant operating 

at 50 percent capacity during the cooler winter months. 

if EPA develops short-term effluent limitations guidelines (e.~., monthly averages and 

daily maximums) for FGD wastewater treatment system effluent, then EPA must characterize 

long-term FGD wastewater treatment system performance and variability of FGD effluent 

characicristics over a period of one year to take into accouni the inherent seasonal variability of 

operating these systems. 

CWAG recommends the following adjustmenis to the sampling plan: 

1. Two consecutive daily samples at each sampling location would be sufficient for the 

initial sampling events scheduled to occur this summer. 

2. EPA should plan return visits to each selected site for additional sampling during at 

least two other seasons. For instance, soine systems could be resampled this fall. For systems 

with biological reactors, UWAG strongly recommends that these systems be resampled during 

winter (i.e., December-February). 

C. Ensuring that FGD WWT Systems are Reasonably Stable is Essential and Depends 

on Many Factors 

The SAP states that "EPA does not intend to collect samples from a wastewater treatment 

system that has not reached steady stale operations because the perforrnance of the system may 

I Other selected facilities inay also have systems with residence iimcs grcaier than four days. UWAG has 

riot done a survey of thc rcsidcncc tiices ibr all seven sciccted f~lcilitics. 
Utiiiw \%brAcf Group 

Mr. Ronald P. Jordan 

April 5, 2010 

Page 4 

not be optimized. Generally, EPA plans to sample FGD wastewater systems that have been 

operating for at leas? six months, or where &ata have shown ihe system to be at steady state." 

(SAP, p. 1-41, UWAG agrees that the wastewater treatment systems to be sampled should be 

reasonably stabie and no longer in start-up mode. However, no arbitrary operational period (e.g., 

six months) is sufficient for determining if a system has reached a level of operation that is 

appropriate for sampling. Many FGD systems have taken much longer than six months to reach 

a reasonably representative operational state. Also, there are many reasons why an FGD system 

-- even one that has been fuliy operational in the past -- may not be reasonably stable at the time 

of sampling. For instance, if a new unit is being added to the treatment system, then the system 

may not be reasonably stable. Also, if the facility has changed coal types or made other 

significant operational changes the system may not he reasonably stable. 

Also, use of the term "steady state" is inappropriate for FGD wastewater treatment 

systems. "Steady state" is typicaily defined as a consistent rate of flow with consistent chemical 

parameter concentrations through the system. However; no FGD wastewater treatment system 

operates this way. Both flow and concentration will vary, and the system wiil never be at 

"steady state" under this definition. 

This is one of the reasons why getting representative samples of FGD wastewater 

treatment systems is so difficult, and why additional samples at a wider variety of treatment 

systems and during different seasons is critically importailt. 

I). EPA Should Collect Paired Samples 

Sampling needs to begin and end on a schedule that accounts for changes in unit load and 

subsequent changes in FGD wastewater treatment flow. It also needs to coinpensate for the 

retention time in the various process vessels. EPA should make every effort to collect paired 

samples of the illfluent and effluent of the FGD wastewater treatment system. It is inappropriate 

to assume steady-state conditions throughout the entire treatment process. For example, if the 

mercury load to the treatment system changes, depending on the residence time of the system, it 

could take 1-3 days for the mercury to move through the system. If paired samples are not 

collected. it is possible to over- or under-estimate the performance of the wastewater treatment 

system. Mercury levels at the effluent could be low when the influent levels are high, and vice 

versa. In addition, determining the mass loadings for constituents such as selenium and nutrients 

for biological treatment will be necessary to characterize changes due to unit load and changes in 

FGD wastewater treatment flow. Although it will take some effort to collect paired samples, it 

will not be possible to make valid comparisons between the influent and effluent samples if 

paired sa~nples are not collected. 
Utiiiry Waler Act Gmup 

Mr. Ronald P. Jordan 

April 5, 2010 

Page 5 

E. EPA Should Collect Representative FGD Influent Samples 

To properly evaluate FCD wastewater treatment system efficiency, a represenlative FGD 

influent sample must be collected. The sample should capture the variability in the waste stream 

during the entire dewatering cycle that typically lasts from two to six hours or even longer. 

Because of differences in the FGD system designs among various power plants, the approach io 

collecting a representative influent sample should be specifically tailored to each piant. For 

plants that have multiple hydroclones to dewater the purge stream(s), the logistics of having to 

collect and then combine multiple samples from these streams is very labor intensive. To 

address this situation, UWAG recommends one of the foilowing approaches, depending on the 

FGD system design and available sample taps. 

1. Collect a single grab at the combined hydroclone overflow pipe sample tap mid-way 

through the dewatering cycle if there is a transfer tank to allow mixing prior to each 

hydroclone in the system. 

2. Collect an equal volume composite sample at the combined hydroclone overflow pipe 

sample cap over the dewatering cycle (3 grabs, I each at the beginning, middle, and 

end) if there is no transfer tank (i.e., no mixing) prior to the hydroclones. 

3. Collect a single grab sample at the equalization (EQ) tank if there is no combined 

hydroclone overflow pipe or sample tap. The EQ iank contains a well-mixed 

composite sample of the hydroclone overflow streams. Because the EQ tank co~ild 

potentially contain recycled streams from within the FGD system, an effort should be 

made to minimize the input of recycled FGD wastewaters into the EQ tank during a 

set period of time prior to the grab sampling event. 

F. For Effluent Samples, EPA Should Use Manual Composite Sampling Rather than 

Automated Composite Sampling 

UWAG agrees with EPA that the FGD efflueni sampling point (SP) should be analyzed 

~ising acomposite sampling method so that the data will be comparable to future permit 

compliance monitoring that may be required at the SP. However, the 24-hour automated 

composite sampling proposed in the SAP has several disadvantages that affect the 

representzativeness of the composite sample, as described below. 

First, an equal time weighted, as opposed to a flow weighied, composite sample will be 

collected. An equal time weighted coinposite will not capture variations in flow and, thus: 
Utility WalerAdGmu:, 

Mr. Ronald P. Jordan 

April 5, 2010 

Page 6 

depending on the variability of the elfluent composition, will not be completeiy representative of 

the FGD effluent waste stream over the 24-hour sampling period. 

Second, automated sampling pumps will malfunction (i.e., tubing kinks or clogs, batteries 

fail, etc.). The experience to date with automated composite sampling at previo~~s EPA sampling 

events (2007 and 2008) showed that approximately 50% (i.e., two out of four automated 

composites attempted) did not operate properly over the 24-hour period. 

Third, automated composite samplers can be difficult and time-consuming to set up 

because different brands and models of pulllps may be used at the varioils power plants. Also: 

personnel time will still be needed over the 24-hour sampling period to monitor the operation of 

the composite samplers and correct any malfunctions. This means that using automated 

composite samplers will require much more personnel time at the site to collect the samples as 

compared to grab composite sampling. 

Fourth, automated discrete samplers are more prone to contamination especially for iowlevel mercury. EPA Method 1631E (reference I) warns against the use of automated composite 

(discrete) samplers. EPA method 1631E section 8.3 states: "NOTE: Discrete samplers have 

been found to conraminate samples with Hg at the ng/L ievel. Therefore, great care should be 

exercised if this type of sampier is used. It may be necessary for the sampling team to use other 

means of sample collection if samples are found to be contaminated using the discrete sampler." 

Depending on the effluent mercury level. the risk of contami~lation could be significant. Also, a 

pumped grab field blank (a snapshot) at the beginning of the 24-hour composite sampiing period 

will not capture the potential sampling contamination over the full 24-hour sampling period. A 

24-hour composite field blank (i.e., blank water pumped over a 24-hour period in the same 

manner as sample collection) should be performed at least once at each site to determine the true 

mercury blank arising from automated composite sampling. 

Fifth, in a complex FGD effiueni matrix, dissolved mercury and metals sampling would 

likely be compromised by 24-hour automated coniposite sampling. Table 11: footnote 7 in the 

 method Update Rule (MUR) (reference 2) states the following: 

For dissolved metals, filter grab samples within 15 minutes of 

collection and before adding preservatives. For a composite 

sample coliected with an automated sampler (e.g., using a 24-hour 

composite sampler; see 40 CFR 122.1 1(g)(7)(i) or 40 CFR Part 

403, Appendix E), fiiter the san~ple within 15 minutes after 

completion of coliection and before adding preservatives. &!& 

known or sus~ected that dissolved sainoie integrilv will be 
UtiiilyrPIater Act Gnup 

Mr. Ronald P. Jordan 

April 5,2010 

Page 7 

comuromised during collection of a composite samnle collected 

auton~aticallv over time (ex., bv interchange of a meVal between -. . 

dissolved and suspended for~lls). collect and filter grab samales to 

be comuosited (footnote 2) in lace of a composite sample 

collected autoiwaticaliy. 

(Emphasis added). if automated composite sampling is used, EPA will be faced with having to 

reject a potentially significant number of 24-hour composite samples due to equipment Failure. 

Also, potential composite sampling contamination as well as dissolved metals and mercury 

partitioning anomalies may go unnoticed. EPA should not under any circumstances accept failed 

composite sainples as equivalent to properly collected 24-hour composite samples. 

Because of the disadvantages summarized above, the safest approach for representative 

FGD effluent composite sampli~lg is to collect four grab sa~nples over a 24-hour period (i.e., one 

set of grabs every six hours). The grabs would then be preserved and gravimetricaily flowproportion composited in the analytical laboratories under clean room conditions. This approach 

is widely used in the analytical laboratory community for compositing low level mercury and 

metals. The advantages of this approach are numerous, as described below. 

First, as mentioned above, grab sampling is the optimal, preferred approach for both tolai 

recoverable and dissolved mercury sampling. The dissolved mercury sampling out of a 24-hour 

composite sample bottle violates the EPA Method 1531E requirement that dissolved mercury 

samples be filtered within 24 hours of sample collection. A portion of the sample will have been 

in the composite bottle for more than 24 hours before filtration. Additionally, the possibility of 

dissolved mercury adsorbing to the composite bottle walls during the 24-hour period is a valid 

concern. For metals, the requirement is to filter dissolved metals within 15 minutes of sample 

collection (MLTR Table II footnote 7). Waiting 24 hours to filter dissolved metals from an 

automated composite sample is a real concerii because of changes in dissolved metals 

partitioning that could occur over that extended period of time. 

Second, the four-grab sample approach is fully compliant with EPA guidance as 

summarized in MUR, Tabie 11 footnote 2 which reads in part: 

if a comuosite measurement is required but a comuosite samnie 

wouid com~romise samole interriiv, individual grab samples must 

be collected at prescribed time i~itervals ie.~.. 4 sarnples over the 

course of a dav. at 6-hour inrervals). Grab samples must be 

analyzed separateiy and tile concentrations averaged. 

Alternatively, grab samples may be collected in the field and 
Mr. Ronald P. Jordan 

April 5, 2010 

Page 8 

composited in the laboratory if the compositing procedure 

produces resulis equivalent to results produced by arithmetic 

averaging of the results of analysis of individual grab samples. For 

examples of laboratory cornpositing procedures, see EPA Method 

1664A (oil and grease) and the procedures at 40 CFR 

141.34(0(14)(iv) and (v) (volatile organics). 

(Emphasis added). Gravimetrically composited samples (i.e., four individual grabs combined 

under clean room conditions into a single analytical sample according to flow-proportioning) 

produce equivalent daia compared to the separate analysis of the four samples followed by 

arithmetic, flow-proportioned compositing (an option described in footnote 2). Gravimetric 

compositing using the four-grab approach will not increase the analytical sample load as 

compared to using an automated composite sampling as currently described in the draft SAP. 

Third, by installing a pre-cleaned pump tubing set at each FGD effluent SP and carefully 

purging the tubing set before each of the four grab sampling events, grab sampling at the FGD 

effluent SP can be simplified. It should be possible to collect the various grabs using a "muitipour" approach that will eliminate the need to do sample splits using a large volume composite 

bottle. This approach would allow fewer people to do the grab sainpling and allow a two team 

approach where one team would collect the first two grabs and a second team collects the last 

two grabs during each 24-hour period. This means that the collection of four separate grabs over 

a 24-hour period will not be more labor intensive than the 24-hour automated composite sampler 

approach requiring periodic monitoring and possibly intervention. 

Fourth, the grab approach will also allow real time grab dissolved melals and mercury 

sanlpling (i.e.. within 15 minutes of sample collection as required in EPA guidance, MUR, Table 

11 footnote 'i), thus eliminating the concern for physical speciation changes when using the 24- 

hour composite bottle sampling approach as currently proposed in the SAP. 

Fifth, the grab approach will produce inore representative samples because a truly flowproportioned composite sample can be produced for ailalysis. Where there is any concern about 

compositing the samples to produce a single anaiytical composite ie.g., for TSS, oil and grease. 

etc.), the11 the four grabs can be analyzed individually and the composite calculated 

arithmetically as described in Table 11 footnote 2. 

We do not know the affect on ihe integrity of the sample by collecting low-level mercury 

through ail automated composite sampler. However, io minimize potential conlamination during 

the collection of automated !ow-level mercury composite samples, a separate, dedicated 
Mr. Ronald P. Jordan 

April 5, 2010 

Page 9 

sampling pump with a glass composite bottle should be used. UWAG strongly recommends use 

of glass for mercury samples as this is consistent with the applicable method. 

6. EPA Should Reduce the Number of Metals Measured 

UWAG has split samples with EPA at six major sampling episodes as well as a smaller 

study. These studies involved the analysis of FGD wastewaters from 13 different plants. Based 

on these studies, UWAG recommends that at least seven metals in the 26 element analyie list in 

the SAP (p. 2-4) be eliminated for the following reasons. 

I. Silver has been universally low in the various split sample studies and is problematic 

to measure accurately because of the highly variable chloride levels among FGD 

wastewaters. 

2. Beryllium has been universally low and usually not quantified in all FGD wastewater 

studies. 

3. Antimony has been universally low in all FGD wastewater studies. In addition, it is 

likely that many of the quantified daia poiilts are overestimates because of antimony's 

strong memory effects that may not have been properly accominodated for by 

adjusting the inter-sample rinse protocol or properly sequencing the various FGD 

sample matrices ji.e., from low to high expected concentrations). 

4. Tin has been universally low and usually not quantified in ail FGD wastewater split 

sample studies. Also, data accuracy is in question because ICP-MS methods 

optimized for other analytes cannot be made compatible with optimal determination 

of tin. 

5. Barium data are unreliable and highly variable because of the elevated sulfate 

concentrations present in FGD wastewaters. Both EPA Methods 200.7 and 200.8 

specifically state that the digestion procedures used "hold in solution only minimal 

concentrations of barium in the presence of free sulfate." 

6. Titanium and aluminum are largely associated with particles, and the dissolved 

titanium and aluminum levels in FGD wastewater are generally very low. Titaniuni 

and aiuminum results from all the studies have been highly variable between methods 

and between laboratories. This variability is more than likely due to the difficulty of 

soiubiiizing particles containing titanium and aluminum during the digestion step. 
Ulilily Water AclGmup 

Mr. Ronald P. Jordan 

April 5, 2010 

Page 10 

7. Lead and cadmium have been universally low, and in many samples not deiecied, in 

FGD influent and effluent samples. 

8. Chromium and vanadium results have been highly variable due to the difficulty in 

solubilizing these constituents during digestion. 

111 summary, these elements could be removed from the analyte list without significa~~tly 

affecting the daia collection effort. This approach would release funds for expanding the number 

of facilities and seasonal periods sampled compromising data usability or diagnostic 

value of the data set in evaluating the efficiencies of various treatment technologies. 

H. Selenium Speciation Measurements Needed to Evaluate Treatability 

The draft SAP does not include selenium speciation analyses as part of the analyte suite. 

Speciation analyses, at least inorganic species (selenate and selenite), should be measured to 

evaluate the treatability of the FGD wastewater being sampled. Selenate and selenite require 

very different approaches to treatment. In addition, selenium speciation is quite variable among 

different plants due in iarge measure to the different oxidation states of the scrubbers. Selenium 

speciation, therefore, call provide essential information needed to evaluate the efficacy of various 

FGD wastewater treatment technologies. 

I. Hexavalent Chromium Method 218.5 Analyses Should Be Confirmed to Validate 

Results 

EPA plans to analyze the samples for hexavalent chromium using EPA Method 21 8.6 or 

another Part 136-approved method. (SAP Table 2-2, p. 2-28.) UWAG is very concerned about 

the reliabiiity of Method 218.6 or any colorimetric method for analyzing hexavalent chromium in 

FGD wastewater. In previous sampling episodes, UWAG unsuccessfully used a coioriinetric 

method (SW-846 7196A) for FGD wastewater. The constituents of the FGD wastewater 

interacted with reagenis used for the colorimetric analysis, ca~ising a precipiiate that interfered 

with the analysis. A colorimetric method was used unsuccessfuily by UWAG in previorrs 

sampling episodes due to precipitation and color changes of the samples during sampie 

preparation. Therefore, EPA should confirm any detectable hexavalent chroinium in all samples 

by validating the res~~lt against the dissolved chromium values iil the same sample. If the 

Meihod 218.5 analyses are not reasonabiy consistent with the dissolved chromiuin values, then 

they should be rejected. 
Mr. Ronald P, Jordan 

April 5, 2010 

Page 11 

J. Cyanide Method 335.4 May Produee False Positives for FGD Wastewater 

Also, EPA plans to anaiyze sampies for cyanide using EPA Method 335.4 or another Part 

136-approved method. UWAG is concerned that Method 335.4 coiild produce false positives for 

FGD wastewater. Research has demonsirated that Method 335.4 can produce false positive 

results from cyanide formation during sample storage at high pH. (Pandil, et al., reference 3.) 

Additionally, Applied Speciation has docume~ited false positives in FGD wastewater samples 

due to the presence of nitrates and nitrites in the samples. Therefore, if EPA retains cyanide 

analysis within the SAP, CWAG urges EPA to provide for confirming analyses that will detect 

any false positives. 

K. Conclusion 

In summary, we would like to emphasize the following issues. 

To capture FGD wasiewater treaiinent system variability, it is essential that EPA: 

a. sample a iarger number of treatmeni systems; 

b. sample all selected FGD wasiewater treatmeni systems over muitiple seasons; 

c. sample across a broader range of coal types; and 

d. sampie intermediate and cycling facilities as well as haseload faciliiies. 

To collect representative sampies of both the FGD influent and effluent, it is essentiai 

that EPA: 

a. collect paired samples to take into account changes in the FGD sysiern, 

particulariy for characterizing biological treatment system perforiiiance; 

b. consider the plant-specific dewatering system design to collect a representative 

influent sample, even if it means collecting multiple grab sainples over the entire 

dewatering cycle; and 

c. coilection of manual composite sampling at the FGD effluent rather than 

automated composite sampling. 

Without these critical adjustments to the sampling program, the resulting data will not reflect 

FGD wastewater treaiment system variability. Unless the true variability of these systems is 
Mr. Ronald P. Jordan 

April 5, 2010 

Page 12 

documented in the sampling program, it will be impossible to set valid elfluent limitations based 

on the data set. 

Please call me if you would like to discuss these comments. 

Sincerely, 

sl -i-i 

Donna B. I-fill 

Chair, Effluent Guideliner Committee 
Mr. Ronald P. Jordan 

April 5, 2010 

Page 13 

References cited: 

1. U.S. EPA. 2002. Method 163 1, Revision E: Mercury in Water by Oxidation, Purge and Trap, 

and Cold Vapor Atomic Fluorescence Spectrometry. EPA-821-R-02-019. Office of Water, 

Engineering and Analysis Division, Washington, DC. 36 pp. 

2. U.S. EPA. 2007. 40 C.F.R. Part 122, 136. et al. Guidelines Establishing Test Procedures for the 

Analysis of Pollutants Under the Clean Water Act; National Prirnary Drinking Water 

Regi~lations; and National Secondary Drinking Water Regulations; Analysis and Sampiing 

Procedures; Final Ruie. Effective 4-1 1-2007. 72 Fed. Reg. 11,200 (March 12,2007). 

3. Pandit, Anita; Young, Connie; Pang, Maria; Khoury: Joseph; Carr, Steve; Fischer, Dwayne; and 

Stahi, James. Factors Affecting Cyanide Generation in Chlorinated Wastewater Effluent Matrix, 

available on the Internet at http://~'~~.w.ccveu.org/p.?s/doc..shtnzl.