# UtilityWaterAct

# GroupG

April 

### 5:2010 Sieeiing!,\odit Cornmillei. Angeia %I. Gioi)iiis, Ciiaiiiiian C.Richaiii i3uieh Rz~yhum L. iiuits Alan E. Gniiiha 1.1.K.IMizk)Gicccoii L>aiid M,LLC iaiiic-,1. Slinc 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 Commentson EPA Draft Generic Sampling andAnalysis 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 SteamElectric 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 SAPbefore beginning the sampling program. The changes we arerecommending wili improve the accuracy, reliability, and representativeness of the overall data produced by the sampling program. 

### A. EPA Should Sampleat

### a Larger Kurnber of 

### Facilities According to the SAP, EPA isplanning 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 areplanning to add new FGD systems, a sample size of seven facilities is inadequateto 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. 20006Mr. Ronald 

### P. Jordan April 

### 5,2010 Page 

### 2

constituents between the dissolved and solid phases. Thus,the selection of FGD systems tobe sampled is critical for characterizingthe range and variability of consticuelltsin FGD wastewaier. Liinestone forced oxidation (LSFO) systems are coiltrolled well for SO2reluoval. 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. Samplingonly seven FGDsystems sinipiy will not demonstrate the true variability of FGD systems across the steam electric industry. Therefore, we urge EPA to increasethe 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 ORPon a routine basis, and most ORP meters in water chemistry labs arenot 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 areplants 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 Facilityburning Powder River Basin (PRB) coal.
We understand that increasing the sample setraises budget concerns. However,this expenditureis necessary to provide appropriate dava to serve as the basis of the rulemaking. Also, as described below, 

### UWAG recommends some changes to the SAPthat 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 EPAthat could be used to fund sampling at a broader range of facilities. 

### B. FourDays of

### SamplingWill 

### Not Capturethe 

### Variability of 

### Systems
For each sampling site,

### EPA plans io collect four consecutive daily samples (SAP, p. 

### 2-61, Collecting four consecutive daily samplesis unnecessarybecause 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 samplinghave 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 chloridein the 

### PRB coal. Also, Duke'sMr. Ronald P. Jordan April 

### 5,2010 Page 

### 3

Belews Creek Station has a hydraulic residence time of 

### 8 days. For 

### FGD syste17z.swith I-esideielzc'e times thnt czre longer thurzfour days, unalyzingfour consecutive daily suwz/~les is essentially tize siirne us clnulyzing,fij~lr uliquots ofrhesanze .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 tobe 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 ofbacteria 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 

### 50percent 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 accounithe inherent seasonal variability of operating these systems. 

### CWAG recommends the following adjustmenisto the samplingplan:
1. Two consecutive daily samples at each sampling location would be sufficient for the initial sampling events scheduledto occurthis summer. 

### 2. EPA should plan return visits to each selected site for additional samplingduring at least two other seasons. For instance, soine systems could be resampled this fall. For systems with biological reactors, UWAG strongly recommends that these systemsbe resampled during winter (i.e.,December-February). 

### C. Ensuring that

### FGD WWT Systems 

### areReasonably 

### Stableis 

### Essential and 

### Depends on Many Factors The SAPstates 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 systemmay

I Other selected facilities inay alsohave 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 &atahave shown ihe systemtobe 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 aremany reasons why an FGD system

-- even onethat 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 thetreatment system,then the system may not be reasonably stable. Also, if the facility has changed coal types or made other significant operational changes the systemmay not he reasonably stable. Also, use of the term "steady state" is inappropriate for 

### FGD wastewater treatment systems. "Steady state" istypicaily 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 sodifficult, 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 schedulethat 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 collectpaired 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 arenot collected. it is possible to over- orunder-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 tocollect paired samples, it will not bepossible to make valid comparisons between the influent and effluent samples if paired sa~nples are not collected.UtiiiryWalerActGmup
Mr. Ronald 

### P. Jordan April 

### 5,2010 Page 

### 5



### E. EPA Should 

### CollectRepresentative 

### FGD Influent Samples
Toproperly evaluate 

### FCD wastewater treatment system efficiency, a represenlative

### FGD influent samplemust 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 shouldbe specificallytailored to each piant. For plants that have multiple hydroclones to dewaterthe 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, 

### UWAGrecommends 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 atransfer tank to allow mixingprior to each hydroclone 

### in the system. 2. Collect an equal volume composite sample at the combined hydroclone overflow pipe samplecap overthe dewatering cycle 

### (3grabs, 

### I each at the beginning, middle, and end) if there is notransfer 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 ofthe hydroclone overflow streams. Because the EQ tank co~ild potentially contain recycled streams from within the 

### FGD system, an effort shouldbe 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 CompositeSampling 

### Rather than Automated Composite Sampling UWAG agrees with EPA that the 

### FGD efflueni sampling point (SP) shouldbe analyzed ~ising a composite sampling method sothat the datawill be comparable to future permit compliance monitoring that may be required at the 

### SP. However, the 24-hour automated composite sampling proposed in the SAPhas several disadvantages that affect the representzativenessof 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:UtilityWalerAdGmu:,
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 samplingperiod. Second, automated sampling pumps will malfunction (i.e.,tubing kinks or clogs,batteries fail,etc.). Theexperienceto 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 ofpulllps may be used at the varioils power plants. Also: personnel time will still be needed over the 24-hour samplingperiod 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 1631Esection 8.3 states: "NOTE: Discrete samplers have been found to conraminate samples with Hg at the ng/L ievel. Therefore, great care shouldbe 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 couldbe significant. Also, a pumped grab field blank (a snapshot) at thebeginning of the 24-hourcomposite sampiingperiod will not capturethe 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 compromisedby 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 15minutes of collection and before addingpreservatives. For a composite samplecoliected with an automated sampler (e.g., using 

### a 24-hour composite sampler; see40CFR 122.11(g)(7)(i)or 40CFR Part 403, Appendix 

### E),fiiter the san~ple within 15minutes after completion of coliection and before addingpreservatives. &!& known or sus~ected that dissolved sainoie integrilv will beUtiiilyrPIaterActGnup Mr. Ronald P. Jordan April 5,2010 Page 7

comuromised during collection of a composite samnlecollected auton~aticallv over time (ex.,bv interchange of a meVal between
-. . dissolved and suspended for~lls). collect and filter grab samales to be comuosited (footnote2) 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 dueto equipment Failure. Also,potential composite sampling contamination as well as dissolved metals and mercury partitioning anomalies may gounnoticed. EPA should not under any circumstances accept failed composite sainples asequivalent toproperly collected 24-hour composite samples.
Because of the disadvantages summarized above, the safest approach forrepresentative 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 samplingis the optimal,preferred approach for both tolai recoverable and dissolved mercury sampling. The dissolved mercury sampling out of a 24-hour composite samplebottle violates the EPA Method 1531Erequirement that dissolved mercury samplesbe filtered within 24 hours of sample collection. A portion of the sample will havebeen in the composite bottle for more than 24 hoursbefore 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 tofilter dissolved metals within 15minutes of sample collection (MLTR Table 

### II footnote 7). Waiting 24 hours to filter dissolved metals from an automated composite sample is a real conceriibecause of changesin 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 

### 11footnote 2 which reads in part: if a comuosite measurement isrequired but a comuosite samnie wouid com~romise samole interriiv, individual grab samplesmust be collected at prescribed time i~itervals ie.~.. 4 sarnplesover 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 andMr. Ronald 

### P. Jordan April 

### 5,2010 Page 

### 8

composited in the laboratory if the compositingprocedure produces resulis equivalent to results produced by arithmetic averaging of the results of analysis 

### of individual grab samples. For examples of laboratory cornpositingprocedures, seeEPA Method 1664A (oil and grease) and the procedures at 40CFR 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 samplesfollowed by arithmetic, flow-proportioned compositing (an option described in footnote 2). Gravimetric compositing using the four-grab approach will not increase the analytical sampleload as compared to using an automated composite sampling as currently described in the draft SAP. Third,by installing apre-cleaned pump tubing set at each FGD effluent SP and carefully purging the tubing setbefore each of the four grab sampling events, grab sampling at the FGD effluent SPcanbe 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 approachwould allow fewerpeople 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 15minutes of samplecollection as required in EPA guidance, MUR,Table 

### 11footnote 'i), thus eliminating the concern for physical speciation changes when using the 24- hour compositebottle sampling approach as currently proposed in the 

### SAP. Fifth, the grab approach will produce inore representative samples because a truly flowproportioned composite samplecan be produced for ailalysis. Where there is any concern about compositingthe samplesto 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 sampleby 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, dedicatedMr. Ronald P. Jordan April 

### 5, 2010 Page 

### 9

samplingpump 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 

### Reducethe Number of 

### Metals Measured UWAG has split samples with EPA at six major sampling episodes as well as a smaller study. These studiesinvolved the analysis of FGD wastewaters from 

### 13different 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 forthe 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 forby adjusting the inter-sample rinse protocol or properly sequencing the various FGD samplematrices 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 cannotbe made compatiblewith 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 ofbarium 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 dueto the difficulty of soiubiiizing particles containing titanium and aluminum during the digestion step.UlililyWaterAclGmup
Mr. Ronald 

### P. Jordan April 

### 5,2010 Page 

### 10



### 7. Lead and cadmium have been universally low, and in many samplesnot 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.
111summary,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 SpeciationMeasurementsNeeded toEvaluateTreatability Thedraft SAPdoes not include selenium speciation analyses as part of the analyte suite. Speciation analyses, at least inorganic species (selenate and selenite), shouldbe measured to evaluatethe 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, callprovide essential information needed to evaluatethe efficacy of various FGD wastewater treatment technologies. 

### I. Hexavalent Chromium Method 

### 218.5 Analyses Should 

### Be Confirmed toValidate 

### Results
EPA plans to analyze the samples for hexavalent chromium using EPA Method 218.6 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-8467196A) for FGD wastewater. Theconstituents of the FGD wastewater interacted with reagenis used forthe colorimetric analysis, ca~ising aprecipiiate that interfered with the analysis. A colorimetric method was used unsuccessfuily by UWAG in previorrs sampling episodes dueto 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 Positivesfor 

### FGDWastewater Also, EPA plans to anaiyze sampies for cyanideusing 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 dueto thepresence of nitrates and nitrites in the samples. Therefore, if EPA retains cyanide analysis within the SAP,CWAGurges EPA toprovide for confirming analyses that will detect any false positives. 

### K. Conclusion 

### In summary, we would like to emphasizethe followingissues.
Tocapture 

### 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 ashaseload faciliiies.
To collect representative sampies ofboth the 

### FGD influent and effluent,it is essentiai that EPA: a. collect paired samplestotake into account changesin the 

### FGD sysiern, particulariy for characterizing biological treatment system perforiiiance; b. considerthe 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 systemsisMr. 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 

### 1631,Revision 

### E: Mercury in Water by 

### Oxidation, Purge and Trap, and Cold Vapor Atomic Fluorescence Spectrometry. 

### EPA-821-R-02-019. Office ofWater, Engineering and Analysis Division, Washington, DC. 36pp. 

### 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. Effective4-1

### 1-2007. 72Fed. 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.