HUNTON& 

WilliAMS 

October 24, 2014 

Via Electronic Mail 

wood.robert@epa.gov 

Mr. Robert K. Wood, Director 

Engineering & Analysis Division (4303T) 

Office of Science and Technology 

U.S. EPA Headquarters 

William Jefferson Clinton Building 

1200 Pennsylvania Avenue, N. W. 

Washington, DC 20460 

HUNTON & WILLIAMS LLP 

RIVERFRONT PLAZA, EAST TOWER 

951 EAST BYRD STREET 

RICHMOND, VIRGINIA 23219-4074 

TEL 804 • 788 • 8200 

FAX 804 • 788 • 8218 

ELIZABETH E. ALDRIDGE 

DIRECT DIAL: 804 • 788 • 8549 

EMAIL: ea1dridge@hunton.com 

FILE NO: 29142.070312 

alicea.jezebele@epa.gov 

Ms. Jezebele Alicea-Virella 

Engineering and Analysis Division (4303T) 

U.S. EPA Headquarters 

William Jefferson Clinton Building 

1200 Pennsylvania Avenue, N.W. 

Washington, DC 20460 

RE: CBI Substantiation Response: Freedom of Information Act (FOIA) 

EPA-HQ-2014-009568 

Dear Mr. Wood and Ms. Alicea-Virella: 

On September 5, 2014, the Utility Water Act Group (UWAG) received your letter 

dated August 29, 2014 asking that UW AG substantiate information claimed as confidential 

business information (CBI) in UWAG' s letter to EPA dated August 1, 2014. The August 1 

letter was in response to EPA's letter ofDecember 30,2013 requesting more information 

about data included in UWAG's comments on EPA's proposed revisions to the steam electric 

effluent limitations guidelines. By letter of September 25,2014, from Kevin Miller, EPA 

Assistant General Counsel, UW AG and its affected members were granted a 20 business day 

extension to the original 15 working day response deadline. 

The UWAG member companies who provided information included in UWAG's 

August 1, 2014 letter hereby waive all CBI designations as to the August 1, 2014 letter. 

This waiver does not apply to any other data or information, including any data or 

information that UW AG member companies may have designated as CBI in response to 

EPA's Questionnaire for the Steam Electric Power Generating Effluent Guidelines (OMB 

Control. No. 2040-0281). 

ATLANTA AUSTIN BANGKOK BEIJING BRUSSELS CHARLOTTE DALLAS HOUSTON LONDON LOS ANGELES 

McLEAN MIAMI NEW YORK NORFOLK RALEIGH RICHMOND SAN FRANCISCO TOKYO WASHINGTON 

www.hunton.com 
HUNTON& 

WILLIAMS 

Mr. Robert K. Wood 

Ms. Jezebele Alicea-Virella 

October 24, 2014 

Page 2 

Please feel free to call me if you have any questions regarding this matter. 

29142.070312 EMF _us 52529252v1 

Very truly yours, 

Elizabeth 

~2~ E. Aldridge 

Counsel to UW AG 
ATLANTA AUSTIN BANGKOK BEIJING BRUSSELS CHARLOTTE DALLAS HOUSTON LONDON LOS ANGELES 

McLEAN MIAMI NEW YORK NORFOLK RALEIGH RICHMOND SAN FRANCISCO TOKYO WASHINGTON 

www.hunton.com 

 

HUNTON & WILLIAMS LLP 

RIVERFRONT PLAZA, EAST TOWER 

951 EAST BYRD STREET 

RICHMOND, VIRGINIA 23219-4074 

TEL 804 • 788 • 8200 

FAX 804 • 788 • 8218 

ELIZABETH E. ALDRIDGE 

DIRECT DIAL: 804 • 788 • 8549 

EMAIL: ealdridge@hunton.com 

August 1, 2014 FILE NO: 29142.070312 

VIA ELECTRONIC MAIL 

Ms. Jezebele Alicea-Virella 

Engineering and Analysis Division CONTAINS CONFIDENTIAL

U. S. EPA Headquarters BUSINESS INFORMATION 

William Jefferson Clinton Building 

1200 Pennsylvania Avenue, N.W. 

Mail Code 4303T 

Washington, DC 20460 

RE: EPA Information Request Regarding UWAG Data for Effluent Guidelines 

 Rulemaking 

Dear Ms. Alicea-Virella: 

Thank you for your interest in the data that UWAG members provided as part of UWAG’s 

comments on the proposed Steam Electric Effluent Guidelines rule (UWAG Comments). 

This letter responds to your information request of December 30, 2013. We believe that the 

data you are reviewing, both our bottom ash transport water characterization data and our data 

showing the absence of sulfides in ash pond discharges, demonstrate that EPA should reevaluate its characterization of bottom ash transport water. 

Bottom Ash Transport Water 

UWAG provided analysis of bottom ash transport water for 21 facilities. (See Attachment 7 

to the UWAG Comments.) We also provided certificates of analysis or certified Form 2Cs 

for all of the samples. (See Attachments 8 and 9 to the UWAG Comments.) 

The UWAG analysis indicates that levels of bottom ash transport water pollutants are far 

lower than EPA’s estimated pollutant levels for bottom ash transport water. 

As we noted in our comments, EPA used outdated bottom ash transport water data (and 

commingled bottom ash and fly ash transport water data) from the 1970s-80s. EPA, 

therefore, proposes to base its regulatory decisions for bottom ash transport water on data 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 2 

collected prior to implementation of the current steam electric effluent guidelines, which were 

promulgated in October 1982. Data which pre-date the 1982 guidelines obviously are not 

representative of current discharges. 

 

In addition, the 1970s-80s data were analyzed using far less sensitive methods than are now 

available, which led to overestimates of pollutants in bottom ash transport water. These errors 

were compounded when EPA used its characterization data to calculate toxic-weighted 

pounds equivalents (TWPEs) for bottom ash transport water, resulting in significant 

overestimates of TWPEs attributable to bottom ash transport water. 

In contrast to the 1970s-80s data, EPA’s analysis of Homer City’s bottom ash transport water, 

based on a single sample collected in August 2007, is very similar to UWAG’s results for all 

parameters except nitrate/nitrite, which is believed to be an error. Even with the error, EPA’s 

results demonstrate very low TWPEs for bottom ash transport water. See UWAG Comments, 

pp. 75-78. 

Since proper characterization data are key to TWPE calculation and thus to the process of 

selecting and limiting pollutants through revised effluent guidelines, UWAG has urged EPA 

to revisit its bottom ash transport water characterization data and its estimates of bottom ash 

transport water TWPEs. 

UWAG is encouraged that EPA is seeking further information on the bottom ash transport 

water characterization data we provided. For the last several months, we have been working 

with members of our group to address EPA’s questions as thoroughly as possible. There are 

some limitations to what we can supply, however, as noted in the next section. 

Confidential Business Information 

On behalf of the members who provided bottom ash transport water data and sulfides data, 

UWAG is asserting a confidential business information claim for a portion of this submittal. 

Attachment 1 to this letter includes plant name, company name, state, plant ICR ID, ICR pond 

SPD number, average annual flow rate, source water, sampling duration and frequency, and 

sampling date for some of the facilities that provided bottom ash transport water samples 

included in the UWAG Comments. Attachment 2 to this letter includes plant name, plant ICR 

ID number, company name, state, ICR SPD ID number, SPD volume, SPD residence time, 

average annual bottom ash sluice flow rate, source water information, and sampling date for 

some of the facilities that provided ash pond samples to be analyzed for sulfides. All of these 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 3 

categories of information, as provided on Attachments 1 and 2, are confidential business 

information because they are competitively sensitive. Coal-fired steam electric units seek to 

market their bottom ash whenever possible. Marketing the ash produces storage and disposal 

savings as well as, in some cases, a revenue stream. The bottom ash transport water 

characterization data and the sulfides data in UWAG’s comments – when combined with 

facility-specific information – is competitively sensitive because ash purchasers routinely 

compare the quality of various sources of coal ash before entering into purchase contracts for 

the ash. The characterization data provided in the UWAG Comments, when coupled with the 

identifying information about specific plants, is a factor that could influence ash purchasing 

decisions. Therefore we are asserting a confidential business information claim on behalf of 

all facilities and companies that provided bottom ash transport water samples and ash pond 

samples used in the UWAG Comments and which are listed in Attachments 1 and 2 to this 

letter. 

In some cases, UWAG members individually decided not to provide the additional 

information which EPA has requested. In those cases, we have answered EPA’s general 

questions in light of the information we have about those facilities, but we have not included 

specific information for those facilities on Attachments 1 and 2. The facilities not providing 

additional plant-specific information are Plants 9, 10, 19, 20, and 21 for the bottom ash 

transport water data and Plants D1, D2, D3, D4, and N1 for the sulfide data. 

Below we respond to EPA’s questions about UWAG’s bottom ash transport water data. 

1. Please provide the plant name and plant location associated with each plant ID 

identified in Attachment 7. In addition, please provide the Pond/Impoundment 

Unit ID (e.g., SPD-2) for the sampled pond, as reported in the Questionnaire for 

the Steam Electric Effluent Guidelines. 

Please see Attachment 1, the bottom ash transport water data summary sheet. In 

consultation with our members, we have provided as much data as possible in 

response to EPA’s questions.

2. Please describe the solids separation processes and treatment procedures 

employed at each power plant for which data are provided. For example, does 

the plant use dewatering bins to separate solids from the ash transport water? 

Please identify if these solids separation processes and/or treatment procedures 

are located upstream or downstream of the sample location. For each plant, 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 4 

please identify what chemicals are added to the wastewater upstream of the 

sample location. 

All 21 plants have ash ponds for solids separation. In addition, Plants 7 and 13 use 

dewatering bins prior to the ash ponds for solids separation. At Plant 7, the sample 

was collected after the dewatering bin (prior to the settling pond) and allowed to settle 

prior to collecting the analytical sample. At Plant 13, the sample was collected at the 

bottom ash pond effluent after dewatering and settling. 

Attachment 1 provides information regarding the sampling location in relationship to 

the solids separation process. Bottom ash sluice water samples (Plants 1-6, 9-11, and 

18-21) were collected at the end of the sluice pipe prior to entering the 

pond/impoundment. No chemicals were added to these ash sluice streams prior to 

entering the pond/impoundment. The samples collected were allowed to settle before 

collecting the analytical sample. 

Bottom ash pond effluent samples (Plants 8, 12, 13, 14, 15, 16, 17) were collected 

after settling at or near the bottom ash pond effluent. All but one of the effluent data 

sets are based on certified Form 2Cs. 

At the time of sampling, only two of the plants (Plants 14 and 17) were adding 

chemicals to the sluice water prior to entering the ash pond to aid in solids settling.1

 

Samples from both plants were collected downstream of the chemical addition and 

solids separation. Plant 14 added anionic and cationic polymers along with sulfuric 

acid to aid in settling and pH adjustment. Plant 17 added a coagulant to the sluice 

water prior to the ash basin to aid in settling. 

3. From which plants and companies did UWAG request bottom ash 

characterization data? If UWAG did not request data from all members, what 

criteria were used to identify the plants for which data were requested? Did any 

plants provide data to UWAG that were not included in UWAG’s Comments to 

EPA? If so, why were these data excluded? 

As explained in the UWAG Comments, we asked all UWAG members to supply 

bottom ash transport water characterization data meeting the following criteria: 

 1

 Plant 17 has been converted to natural gas and no longer uses the chemical additives in question. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 5 

1. The bottom ash transport water should not be comingled with other wastestreams, 

such as fly ash transport water, FGD wastewater, or cooling water. 

2. If possible, the average annual discharge flow from the bottom ash pond should be 

included. 

3. If possible, the data should include an analysis of the pollutants in the source water 

(i.e., river water) used to sluice the bottom ash. 

4. The water samples should be analyzed using sensitive methods, such as Method 

200.8 or 200.7, for metals and Method 1631E or equivalent for mercury. 

5. For facilities that do not have separate bottom ash ponds, UWAG advised that 

bottom ash sluice water samples should be collected at the end of the sluice pipe 

prior to entering the pond to collect a sample that has not been commingled with 

other wastestreams. These sluice water samples were allowed to settle for 

approximately one hour before drawing off the supernatant for analysis. 

6. UWAG requested that its members provide laboratory reports or certificates of 

analysis for all characterization data. 

See UWAG’s Comments, p. 58. Using these criteria, UWAG reviewed all data 

received from members. We then rejected any data that failed to meet the criteria. 

For example, we did not use any data for samples that reflected comingled bottom 

ash and fly ash samples, and we did not use any samples in which water from other 

processes was used as sluice water, except that Plant 2 uses condenser cooling 

water for sluicing and Plant 19 uses cooling tower blowdown for sluicing. We 

selected samples from Plants 2 and 19 because the plants initially indicated river 

water as the source for sluicing bottom ash. Later, after the comments were filed, 

we learned that the plants use river water for sluicing but only after it is used as 

condenser cooling water. Therefore, the sluice water which originates from the 

river is technically condenser cooling water. We also rejected any mercury data 

that were not analyzed by a low-level method (Methods 1631E, 245.7 or an 

equivalent). Mercury data from seven plants were not used due to high MDLs. 

All of the results from these plants were reported as <MDL of 0.2 ppb. The source 

water for these plants were also reported as <MDL of 0.2 ppb. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 6 

4. Is the median source water and bottom ash sluice water concentrations provided 

for the dataset calculated using all individual samples (i.e., the entire dataset) or 

using the plant averages? 

As explained in our comments, if a facility provided more than one sample for the 

same outfall, we averaged those samples to obtain the pollutant concentration. See 

UWAG Comments, p. 58. All averages in the UWAG dataset represent an average of 

results for the same outfall only, and not an average across the entire dataset. To be 

conservative, UWAG used the detection level (MDL) as the concentration for 

pollutants that were not detectable. This virtually guarantees that the calculated 

concentrations are higher than the actual ones. 

5. For each pond where the data you submitted is comprised of multiple sample 

results, please provide the pollutant concentration data for each individual 

sample. 

We provided this information in our comments. See UWAG Attachment 8, 

“Supporting Documentation for UWAG Bottom Ash Characterization Table Sluice 

Water/Pond Discharge,” and UWAG Attachment 9, “Supporting Documentation for 

UWAG Bottom Ash Characterization Source Water.” All quality control data 

submitted to UWAG were also included in these attachments. 

6. For plants that list the bottom ash transport water sampling location as “BA 

Sluice Pipe” (Plants 1, 2, 3, 4, 5, 6, 9, 10, 11, 18, 19, 20, & 21), please explain why 

ash pond effluent concentrations were not provided. 

The listed plants do not have a dedicated bottom ash settling pond. Therefore, any 

sample of ash pond effluent would not represent bottom ash transport water, but the 

pollutant levels of the wastewaters (which might include fly ash transport water, 

cooling water, etc.) comingled in the pond. For these plants, as noted in our list of 

bottom ash transport water criteria, members collected bottom ash sluice water 

samples at the end of the sluice pipe prior to entering the ash pond. For this plant 

configuration, the sample that would best represent bottom ash transport water is a 

composited and settled sample from the end of the bottom ash sluice pipe prior to 

entering the ash pond. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 7 

7. For each plant, please provide additional details regarding the sampling 

locations. 

a. Source water 

i. Please specify the location of the source water samples provided 

(e.g., Ohio River upstream of plant, Ohio River at point of intake to 

plant (note if intake is upstream or downstream of plant 

discharges), piping prior to mixing with bottom ash). 

ii. Does the plant treat the intake water prior to use in the bottom ash 

sluicing system? If so, how is the intake water treated? 

iii. Does the plant recycle any process wastewater for use in the bottom 

ash sluicing system? If so, how? 

b. Bottom ash transport water 

i. Please specify the location of the bottom ash sample provided (e.g., 

for “bottom ash sluice pipe” please identify if the sample was 

collected immediately after mixing or coming out of the pipe at the 

pond influent). 

ii. For each ash pond, please identify all wastestreams that enter the 

ash pond and their relative contribution (flow rates, pollutant 

concentrations, and pollutant mass loads) to the pond. 

a. Source Water 

Attachment 1 provides information on the sampling location of source water samples. 

UWAG members collected source water samples either at the plant intake or from a 

service water tap (if available). UWAG requested that the source water sample 

represent the water used to sluice the bottom ash to the pond. All of the plants, except 

Plants 2 and 19, use river water to sluice bottom ash. Plant 2 uses once-through 

condenser cooling water for sluicing while Plant 19 uses cooling tower blowdown. 

Plant 1 uses river water for sluicing bottom ash, but the intake water is downstream of 

the plant’s primary wastewater discharge. 

None of the plants treat their source water prior to using it for sluicing. Only one of 

the plants (Plant 13) that provided bottom ash transport water samples recycle the ash 

pond water (i.e., reuses it for continued sluicing of bottom ash.) All of the plants, 

except Plants 1, 18, and 19, withdraw river water upstream of the plant discharges. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 8 

Again Plant 2 uses once-through condenser cooling water and Plant 19 uses cooling 

tower blowdown for bottom ash sluicing, therefore the source water is considered a 

process wastewater. Plants 1 and 18 use river water for sluicing bottom ash, but the 

intake water is downstream of the plant’s primary wastewater discharge. 

b. Bottom Ash Transport Water Samples 

See our response to question 2 above for a description of the BATW sample location 

and collection protocols. For the bottom ash pond effluent samples, we obtained the 

BATW characterization data from each plant’s Form 2C. See Attachment 8 to the 

UWAG Comments, which includes the Form 2Cs. UWAG did not collect flow rates 

and pollutant concentrations for other wastestreams entering the pond. However, in 

response to EPA’s questions, we asked the individual facilities to provide information 

about the other wastestreams entering the pond and the annual average flow rate for 

the pond. See Attachment 1 for a summary of this information. 

8. For each plant, please provide the associated TSS concentration for the source 

water (before and after any treatment prior to its use for transporting ash) and 

the bottom ash samples. 

UWAG did not ask members to measure the TSS concentration in the source water. 

Some plants provided source water TSS concentrations, and those were provided in 

the Certificates of Analysis in Attachment 9 of the UWAG Comments. In response to 

EPA’s questions, UWAG gathered additional information on the TSS for some of the 

subject plants which is provided in Attachment 1. 

9. Please provide a more detailed description of the “sampling method” field, as 

well as a description for each of the identifiers included in the spreadsheet (e.g., 

“multiple grabs & composited,” “settled”). In addition, please provide duration 

and frequency information for composite sampling (e.g., 24-hour composite 

collected every hour). 

The description of the sampling method provided to EPA in Attachment 7 of the 

UWAG Comments was not entirely clear. The supplemental information provided in 

Attachment 1 should clarify the description of the sampling location and its 

relationship to the solids separation process and treatment (if any). 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 9 

Some of the data for the individual plants are averages of single grab samples taken at 

different units and/or different days. Some of the data represent composite samples 

composed of grab samples taken over the bottom ash sluicing period. Attachment 1 

provides the duration and frequency for the composite samples. 

10. For each plant, please describe any atypical operations occurring at the plant at 

the time of sampling (e.g., test bum of new coal). 

No abnormal conditions were noted during sample collection except for one sample 

of bottom ash pond effluent collected from Plant 12. This sample was collected 

during the excavation of the ash pond and does not represent normal treatment by 

settling. However, this sample was included in the averages provided to EPA for 

Plant 12. 

11. For each plant, please provide the flow rate of the wastewater at the time of 

sampling, as well as the average annual bottom ash discharge flow rate. 

UWAG did not request that its participating members measure flow rate at the time 

of sample collection. Plants 12, 14, and 15 provided the average annual bottom ash 

discharge flow rates on their Form 2Cs, which were submitted as part of Attachment 

8 to the UWAG Comments. In response to EPA’s questions, UWAG gathered 

additional information on the average annual flow rates and provided it in 

Attachment 1. 

12. Do any of these data correspond to data included in EPRI PISCES reports? If 

so, please identify which Plant ID and the corresponding PISCES report. 

UWAG’s bottom ash transport water characterization data is entirely distinct from the 

data in the EPRI PISCES reports. 

13. A previous version of the table included in Attachment 7 was provided to the 

Small Business Association (SBA) during interagency review of the proposed 

steam electric ELGs. There, the table included a footnote “Note 1 - Multiple 

grabs of bottom ash sluice water were sampled throughout the sluicing period 

and composited. Then, the composite was allowed to settle at least one hour prior 

to sampling the supernatant.” Please identify which, if any, plants used this 

procedure for collecting the samples. Please provide justification that the 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 10 

approach described in Note 1 is comparable to the actual performance expected 

in the surface impoundments at the plants for which the samples represent. 

Only ash pond effluent samples from plants with primarily bottom ash transport water 

were included in the UWAG data. The sampling approach described in the table’s 

footnote (Note 1) was the recommended UWAG protocol provided to plants that 

commingle fly ash water, cooling water or FGD wastewater in the same pond as the 

bottom ash water. The ash pond effluent from these plants (i.e., plants that treat fly 

ash, bottom ash and cooling water in the same pond) would not be representative of 

bottom ash transport water. Plants that used the UWAG protocol were 3, 9, 10, 11, 20 

and 21. Plants 1, 2, 4, 5, 6 and 7 also collected bottom ash sluice water samples at the 

end of the pipe prior to entering the pond for the same reason; however these samples 

were grabs instead of composite samples. UWAG believes that the data representing 

settled bottom ash sluice water collected at the end of the sluice pipe prior to entering 

the pond are comparable to the actual treatment performance expected from a bottom 

ash settling pond (i.e., bottom ash pond effluent). Additional data will be submitted to 

EPA in the near future to demonstrate that this sampling approach is comparable to the 

actual performance expected in the surface impoundments.

In addition, the bottom ash sluice water data collected for the UWAG Comments 

contain more quantified data (i.e., data above the quantification limits) than the bottom 

ash effluent data taken from the Form 2Cs. The Form 2C data contain more nondetect data and the detection limits for some of the pollutants, such as silver, are much 

higher than the detections limits reported for the bottom ash sluice water data. 

Therefore, the average concentrations for some of the pollutants in the effluent 

samples are artificially higher. However, to be conservative, UWAG used the 

detection limit value to calculate the average concentrations.

14. In addition, the data provided in Attachment 7 differs from the data included in 

the previous version of the table submitted to SBA (described in Question 12) for 

Plants 2, 15, and 21. Please provide an explanation for the differences between 

these reported values. 

The table provided for the OMB meeting (which was labeled “Draft”) was 

preliminary. As UWAG continued to review and collect data, it updated the table. 

Thus, the preliminary table is different from the one submitted as an attachment to the 

UWAG Comments. A more detailed explanation of the changes to the data for Plants 

2, 15, and 21 is provided below. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 11 

Plant 2 – The data in the draft table represent one bottom ash sluice water grab sample 

collected at the end of the sluice pipe prior to entering the pond. The final data 

submitted with the UWAG Comments represent an average of three bottom ash sluice 

water grab samples collected on the same day and analyzed separately. 

Plant 15 – UWAG replaced the data in the draft table with another set of data from the 

same plant because the Certificate of Analysis could not be found to validate the data 

provided to UWAG. The data provided in the UWAG Comments represents a bottom 

ash pond effluent sample that was reported in the Form 2C permit application. 

Plant 21 – The data in the draft table are an average of four bottom ash sluice water 

composite samples collected at the end of the sluice pipe prior to entering the pond. 

The data submitted with the UWAG Comments are an average of six composite 

samples, including the original four samples. The Certificates of Analysis for all six 

composite samples were provided in Attachment 8 of the UWAG Comments. 

Sulfides Data 

EPA estimated that sulfides in bottom ash transport water accounted for 1,587,993 

TWPEs per year which accounts for 58% of the total TWPEs for bottom ash transport 

water. This level of loading –if it were true –would make sulfides the largest 

contributor of TWPEs for bottom ash transport water by far. As part of EPA’s 

Sensitivity Analysis Evaluating the Effect of Nondetect Results in the Ash Loadings 

Model, April 19, 2013 (DCN SE03882), EPA looked at the change to the baseline ash 

loadings if sulfide was excluded from the ash loadings. EPA considered the impacts 

of the limited sulfide data when evaluating bottom ash loadings. If EPA had 

eliminated the sulfide data, its conclusion on bottom ash transport water would have 

been very different. As explained in UWAG’s Comments, EPA’s sulfides TWPEs do 

not withstand scrutiny. In brief, here are the reasons why. 

1. EPA chose three sulfide values from Form 2C data that were ostensibly “detected.” 

These three values are the basis for all of EPA’s sulfide estimates. But for each of the 

three samples, the Form 2C provided corresponding source water data that indicated 

sulfide was also present in the river water at essentially the same concentrations. 

Since sulfide is formed only under anoxic conditions, the intake results were most 

likely false positives, probably due to analytical interferences, and thus the effluent 

sulfide results are likely false positives too. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 12 

2. Some plants aerate their discharges prior to or at the discharge point to further 

increase the oxygen content of the water, and in other cases the construction of the 

discharge point is such that aeration of the discharge is increased. In these cases, 

sulfides are unlikely to be present in ash pond discharges. 

3. There are documented problems with false positives from some sulfide analytical 

methods, as explained in the UWAG Comments. For example, the most commonly 

used analytical methods for sulfides are colorimetric methods, Method 376.2 and the 

20th Ed. SM-4500-S2 D. The colorimetric methods have lower detection limits than 

other methods, but can produce false positive results due to various types of 

interferences, most notably turbidity and total suspended solids. 

UWAG decided to analyze for sulfides in ash ponds to determine if it is a common 

pollutant. The results of our analyses are presented in Attachment 5 of our comments. 

As stated in Attachment 5, we believe this study conclusively refutes the EPA estimate 

of average concentrations of sulfide up to 1 mg/L being consistently discharged from 

ash ponds. 

The evidence suggests that sulfide is in fact not present at all in the ponds. High 

dissolved oxygen was found in all of the samples associated with the ash transport 

process, including the ponds themselves. Since sulfides form only in anoxic 

conditions, the presence of high dissolved oxygen is further proof that sulfides are not 

present. 

Additionally, the titration and field colorimetric results were all below the detection 

limit. Even with the colorimetric analysis, there were no results above the laboratory 

quantitation limit and the same “J” flagged detections were also reported for the 

upstream river water. When EPA evaluated its own data for other pollutants, it 

considered values below the laboratory quantitation limit to be non-detected results. 

Below we respond to EPA’s questions about UWAG’s sulfide data. 

1. Please provide the plant name and plant location associated with each plant ID 

identified in Attachment 5. In addition, please provide the Pond/Impoundment 

Unit ID (e.g., SPD- 2) for the sampled pond, as reported in the Questionnaire for 

the Steam Electric Effluent Guidelines. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 13 

In consultation with our members, we have provided as much data as possible in 

response to EPA’s questions. See Attachment 2. 

2. What are the current solids separation processes and treatment procedures 

employed at each power plant for which data are provided? Please identify if 

these solids separation processes and/or treatment procedures are located 

upstream or downstream of the sample location. For each plant, please identify 

what, if any, chemicals are added to the wastewater upstream of the sample 

location. 

All nine plants sampled for sulfides use settling ponds for solids separation. Plant M1 

uses a dewatering bin followed by a settling pond to remove bottom ash. Two plants 

(Plants E1 and G1) add ferric chloride to the ash pond to aid in metals removal. The 

remaining seven plants do not use any chemical addition. See Attachment 2 for 

information regarding the sampling location and its relationship to the solids 

separation process and chemical treatment. 

3. From which plants/companies did UWAG request sulfide characterization data? 

What criteria were used to identify the 9 plants chosen for sampling? 

UWAG made a general request to all members to offer ash ponds for sulfides testing. 

Nine plants volunteered to conduct the sampling and send the samples to the selected 

laboratory (Empirical Laboratories) for analyses. Empirical agreed prior to sampling 

to perform all of the sulfide analyses and interference removal procedures requested, 

including the selective ion electrode method. 

4. What is the depth, volume, and residence time for the surface impoundments 

from which samples were collected? 

UWAG did not request the depth, volume, and residence time for the surface 

impoundments sampled for sulfides. Some of this information may be available in 

responses to EPA’s ICR. The pond’s residence time and the original and current 

pond/impoundment dimensions can be found in the plant’s response to ICR, Questions 

D4-2 and D4-3, respectively. Table D-5 includes volume, surface area, bottom 

elevation, top elevation, freeboard height, etc. for the pond. 
Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 14 

5. For each plant, please provide further additional details regarding the sampling 

locations. 

a. Source water 

i. Please specify the location of the source water samples provided 

(e.g., Ohio River upstream of plant, Ohio River at point of intake to 

plant (note if intake is upstream or downstream of plant 

discharges), piping prior to mixing with bottom ash). 

ii. Is intake water treated prior to use in the bottom ash sluicing 

system? If so, please describe the treatment process. 

iii. Does the plant recycle any process wastewater for use in the bottom 

ash sluicing system? If so, how? 

See Attachment 2 for information requested regarding the specific sampling location 

of the source water samples. None of the source water samples were treated prior to 

use in the bottom ash sluicing system. Only one of the nine plants uses process 

wastewater in the bottom ash sluicing system. Plant M1 recycles ash pond water for 

sluicing ash and uses river water as makeup to the system. 

b. Bottom ash transport water 

i. Please specify the location of the bottom ash sample provided for 

Plants D1, D2, D3, and D4 (e.g., ash pond near effluent). 

ii. For ash pond effluent samples, please identify all wastestreams that 

enter the ash pond and their relative contribution (flow rates, 

pollutant concentrations, and pollutant mass loads) to the pond. 

iii. Please identify which ash pond samples were collected at a depth 

near the bottom of the pond and the depth at which the sample was 

collected.

See Attachment 2 for information requested regarding the specific sampling location 

of the ash pond samples. UWAG did not request flow rates, pollutant concentrations, 

and mass loads for wastestreams that enter the ash pond; however, as noted in 

Attachment 2, we have collected some additional information in response to EPA’s 

questions. For the samples collected in the middle of the pond, the samples were 

collected about 1-2 feet below the surface of the pond.
HUNTON& 

WILLIAMS 

Ms. Jezebele Alicea-Virella 

August 1, 2014 

Page 15 

6. For each plant, please describe any atypical operations occurring at the plant at 

the time of sampling (e.g., test burn of new coal). 

No atypical operations were noted during sample collection. 

7. For each plant, please provide the flow rate of the wastewater at the time of 

sampling, as well as the average annual bottom ash discharge flow rate. 

UWAG did not request that the volunteer facilities measure flow rate during the 

sampling event or provide average annual bottom ash discharge flow rates. Average 

flow rates for 2009 can be found in the ICR. However, the flow rates in the ICR may 

not be typical of the flow rates at these facilities. Due to decreased operations of coalfired plants due to the competitive natural gas prices, the flow rates may have 

decreased significantly. 

8. Please explain the meaning of the asterisk(*) next to "Field Sulfide" in Field Test 

Data Table 1. 

The asterisk refers to the footnote at the bottom of the table. The asterisk was 

inadvertently left off the footnote. "Field Sulfide" indicates that sulfide was analyzed 

in the field using a LaMotte Sulfide Field Test Kit in accordance with SM 4500S2D. 

~[~ Elizabeth E. Aldridge 

Attachments 

29142.070312 EMF _us 51536421v3 
*All information in colums labeled "CBI" is confidential business information Attachment 1

Bottom Ash Transport Water Data Summary Sheet

Plant

Number

CBI

Plant Name

CBI

Company

CBI

State

CBI

ICR Plant

ID

CBI

ICR Pond SPD # BATW ‐ Sampling Location BATW ‐ Sample Representation

Annual 

1 Widows Creek TVA AL 6257 SPD‐1 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water 1219 MGY 

rate fo

2 Bull Run TVA TN 9481 SPD‐1 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water 241 MGY 

rate fo

3 Yates Georgia Power GA 6370 SPD‐2 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water 277 MGY 

rate fo

4 EC Gaston Alabama Power AL 928 SPD‐1 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water 390 MGY 

rate fo

5 Gorgas Alabama Power AL 4599 SPD‐6 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water 450 MGY 

rate fo

6 Greene County Alabama Power AL 6368 SPD‐1 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water 201 MGY 

rate fo

7 Crist Gulf Power FL 4702 SPD‐1 Hydrobin Effluent / Pond Influent Settled Bottom Ash Sluice Water 197 MGY 

rate fo

8 Kammer AEP WV 2149 SPD‐1 BA Pond Effluent Sample represents bottom ash pond effluent. No other wastestreams enter the bottom ash pond. Bottom 

maximum 

11 Monroe DTE MI 4533 SPD‐4 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water 430 MGY b

flow rate 

12 Ratts Generating Station Hoosier Energy IN 2314 1 BA Pond Effluent

Sample represents bottom ash transport water.

Infrequently: Coal pile runoff; metal cleaning

wastes.

13 River Rouge DTE MI 9120 Pond 1 BA Pond Effluent

Sample represents 90% bottom ash sluice waterand 10% fly ash silo wash down. Infrequently: non‐

chemical metal cleaning wastes are discharged into

Pond 1 about twice a year. At the time the sample

was collected, there was no recent non‐chemical

metal cleaning waste input to the basin.

180 MGY b

flow rate 

14 Meredosia Ameren IL 4764 2 BA Pond Effluent

BA Sluice‐0.238 mgd, Ash Hopper Water Seals‐

0.664 mgd, Heat exchanger‐0.798 mgd, Boiler

Room Sumps and Drains‐0.684 mgd, various other

LVW Streams ‐ intermittent flows

Doc ID # 51044770 
*All information in colums labeled "CBI" is confidential business information Attachment 1

Bottom Ash Transport Water Data Summary Sheet

Plant

Number

CBI

Plant Name

CBI

Company

CBI

State

CBI

ICR Plant

ID

CBI

ICR Pond SPD # BATW ‐ Sampling Location BATW ‐ Sample Representation

Annual 

15 Sioux Energy Center Ameren MO 8902 1 BA Pond Effluent

BA Sluice‐4.35 mgd, Drain Sump‐0.535 mgd,

stormwater runoff‐0.078 mgd, other Intermittant

flows

16 Burlington Alliant Energy IA 189 SPD‐4 BA Pond Effluent (Outfall 001)

Bottom ash and economizer ash sluice (2.87 mgd),

Floor Drains and RO Reject (0.12 mgd), Ash Seal

System (0.684 mgd). Infrequently: Stormwater

Runoff (1.07 mgd), Coal Pile Runoff (0.394 mgd),

Rinsate from Chem Cleaning (0.02 mgd).

Bottom a

17 Dubuque Alliant Energy IA 1754 SPD‐1 BA Pond Effluent (Outfall 002)

Primarily composed of bottom ash sluice waters ‐ 0.091 mgd average flow for 365 days per year.

Stormwater runoff (10 yr storm event only).

Bottom a

18 Kingston TVA TN 265 SPD‐1 End of BA Sluice Pipe / Pond Influent Settled Bottom Ash Sluice Water Bottom as

58

Doc ID # 51044770 
*All information in colums labeled "CBI" is confidential business information Attachment 1

Bottom Ash Transport Water Data Summary Sheet

Plant

Number

CBI

Plant Name

1 Widows Creek

2 Bull Run

3 Yates4 EC Gaston

5 Gorgas6 Greene County

7 Crist8 Kammer

11 Monroe12 Ratts Generating Station

13 River Rouge

14 Meredosia

Treatment location in relation to sampling

location

BATW ‐ 

Composite or

Grab

BATW ‐ Sampling

Method

CBI

BATW ‐ Sampling

Duration & Frequency

BATW ‐ 

Number of

Samples

Used in

Average

CBI

BATW ‐ Sampling

Date(s)

BATW ‐ TSS

(ppm)

Aty

T

Samples were collected at end of the bottom ash

sluice pipe prior to entering the pond. Treatment

is settling pond downstream of sample point. Grab Grab Grab samples taken from two separate units 2 09/14/2010 190 ppm ‐ settled BA sluice water 

Samples were collected at end of the bottom ash

sluice pipe prior to entering the pond. Treatment

is settling pond downstream of sample point. Grab Grab Single grab samples 3 03/24/2010 585 ppm ‐ settled BA sluice water 

Samples were collected at end of the bottom ash

sluice pipe prior to entering the pond. Treatment

is settling pond downstream of sample point. Composite UWAG Protocol

14 grab samples

collected over 55 minute

sluice period

1 01/11/2012 31 ppm ‐ settled BA sluice water 

Samples were collected at end of the bottom ash

sluice pipe prior to entering the pond. Treatment

is settling pond downstream of sample point. Grab Grab Single grab samples on multiple days from

separate units

6

3/8/2011 (2 samples

from different units),

3/10/2011 (1 unit),

7/5/2011 (3 samples

from different units)

Not analyzed 

Samples were collected at end of the bottom ash

sluice pipe prior to entering the pond. Treatment

is settling pond downstream of sample point. Grab Grab

Single grab samples

collected from 2 separate

units

3 8/30/2011, 8/31/2011 Not analyzed 

Samples were collected at end of the bottom ash

sluice pipe prior to entering the pond. Treatment

is settling pond downstream of sample point. Grab Grab

Single grab samples

collected from 2 separate

units

2 08/24/2011 Not analyzed 

Sample was collected at the hydrobin effluent prior

to entering the pond. Treatment is dewatering bin

and settling pond downstream of sample point. Grab Grab Single grab sample 1 04/25/2012 6 ppm ‐ Hydrobin effluent 

Bottom ash pond effluent samples were collected

from the end of the pipe leaving the bottom ash

pond. Grab

Two single grab

samples using

clean hands, dirty

hand procedures

Two single grab samples 2 10/09/2012 Not analyzed 

Sample was collected prior to any treatment.

Collected at end of bottom ash sluice pipe prior to

entering the ash basin. Composite UWAG Protocol 12 grabs (~1000 ml ea) over one hour period 1 11/05/2012 Not analyzed; 13 ppm monthly

average in 2013

Samples were collected near the bottom ash pond

effluent. Grab Grab Single grab Varies 1‐32 9/2008 ‐ 12/2009 8

1 of 

ab

07

Sample was collected from the discharge weir of

Pond 1. The plant uses dewatering bins prior to

discharging bottom ash sluice water to Pond 1.

Composite Composite Information not available 1 11/28/2001 Not analyzed 

Sample collected after settling. Sulfuric acid is

added approximately 25 feet from effluent weir.

Polymers added at the influent to the

impoundment.

Grab Grab Single grab 1 03/23/2010 7.6 

Doc ID # 51044770 
*All information in colums labeled "CBI" is confidential business information Attachment 1

Bottom Ash Transport Water Data Summary Sheet

Plant

Number

CBI

Plant Name

15 Sioux Energy Center16 Burlington17 Dubuque18 Kingston

Treatment location in relation to sampling

location

BATW ‐ 

Composite or

Grab

BATW ‐ Sampling

Method

CBI

BATW ‐ Sampling

Duration & Frequency

BATW ‐ 

Number of

Samples

Used in

Average

CBI

BATW ‐ Sampling

Date(s)

BATW ‐ TSS

(ppm)

Aty

T

Sample collected after settling. No chemical

treatment. Composite Composite

Eight flow‐proportional

grabs during 24 hour

period

1 05/29/2008 54 

Samples were collected downstream of settling

pond.

Composite Automated Sampler 24‐hour composite (multiple grabs at 15 minute intervals) 1 11/10/2010 31.04 (long‐term average) 

No chemical additives used. However a coagulant

is injected upstream of ash pond to aid in solids

settling. Sample was collected downstream of

solids settling.

Composite Automated Sampler 24‐hour composite (multiple grabs at 15 minute intervals) 1 03/07/2007 6.45 (long‐term average) 

Samples were collected at end of the bottom ash

sluice pipe prior to entering the pond. Treatment

is settling pond downstream of sample point. Grab Grab Grab samples taken from two separate units 2 08/26/2010 12 

Doc ID # 51044770 
*All information in colums labeled "CBI" is confidential business information Attachment 1

Bottom Ash Transport Water Data Summary Sheet

Plant

Number

CBI

Plant Name

1 Widows Creek

2 Bull Run

3 Yates4 EC Gaston

5 Gorgas6 Greene County

7 Crist8 Kammer

11 Monroe12 Ratts Generating Station

13 River Rouge

14 Meredosia

CBI

Source Water ‐ 

Sampling Date

Source Water ‐ 

Sampling Location

Intake Water Upstream of Plant

Discharges?

Source Water ‐ 

Treatment

Source Water ‐ 

TSS (ppm)

09/14/2010

At the intake tunnels

upstream of the

condensers

No, downstream of plant's primary

wastewater discharge No treatment 2.5

03/24/2010

At the intake tunnels

upstream of the

condensers

Yes No treatment 6.6

01/11/2012 Tap at the service water tank Yes No treatment 6

Not available River intake, upstream of plant Yes No treatment Not analyzed

Not available River intake, upstream of plant Yes No treatment Not analyzed

Not available River intake, upstream of plant Yes No treatment Not analyzed

04/25/2012 River intake, upstream of plant Yes No treatment 11

10/09/2012

Plant intake, upstream of

discharges except

sewage treatment

discharge

Yes, except sewage treatment

discharge No treatment Not analyzed

11/05/2012

Plant's intake bay just

prior to general service

water pump

Yes No treatment Not analyzed

9/2008 ‐ 12/2009 River water intake

All process wastewater dischargesdownstream of intake. One storm

water discharge upstream from

parking lot/roads.

No treatment Not analyzed

11/28/2001

Plant's intake bay just

prior to general service

water pump

Yes No treatment Not analyzed

03/23/2010 Plant raw water intake Yes No treatment 15

Doc ID # 51044770 
*All information in colums labeled "CBI" is confidential business information Attachment 1

Bottom Ash Transport Water Data Summary Sheet

Plant

Number

CBI

Plant Name

15 Sioux Energy Center16 Burlington17 Dubuque18 Kingston

CBI

Source Water ‐ 

Sampling Date

Source Water ‐ 

Sampling Location

Intake Water Upstream of Plant

Discharges?

Source Water ‐ 

Treatment

Source Water ‐ 

TSS (ppm)

05/29/2008 Raw water treatment influent No, however 87x dilution from the Mississippi River No treatment 87

11/09/2010 River water intake Yes No treatment 76

03/07/2007 River water intake Yes No treatment 316

08/27/2010 Once‐Through Condenser return culvert No, downstream of plant's primary wastewater discharge No treatment 1.8

Doc ID # 51044770 
* All information in columns labeled "CBI" is confidential business information

Attachment 2

Sulfides Data Summary Sheet

Plant ID CBI Plant Name CBI Plant ICR ID CBI Company CBI State CBI SPD ID Solids Separation Process SPD Depth (ft) CBI SPD Volume (ft3)

CBI

SPD

Residence

Time

(days)

Ash Transport Water ‐ Sulfide Sam

Location

A1 Kyger Creek AEP OH SPD‐1 Settling NA NA NA End of BA Sluice Pipe / Pond Influen

A1 Kyger Creek AEP OH SPD‐1 Settling Varies 3,515,200 15.29 BA Pond Near Effluent 

A1 Kyger Creek AEP OH SPD‐2 Settling NA NA NA End of FA Sluice Pipe / Pond Influen

A1 Kyger Creek AEP OH NA NA NA NA NA Source Water 

E1 EC Gaston APC AL NA NA NA NA NA Source Water E1 EC Gaston APC AL SPD‐1 Settling NA NA NA End of BA Sluice Pipe / Pond Influen

E1 EC Gaston APC AL SPD‐1 Settling NA NA NA End of FA Sluice Pipe / Pond Influen

E1 EC Gaston APC AL SPD‐1 Settling NA NA 1.3 Ash Pond ‐ Middle of Pond 

E1 EC Gaston APC AL SPD‐1 NA Not available 499 million 1.3 Ash Pond Near Effluent 

M1 Miller APC AL NA NA NA NA NA Source Water M1 Miller APC AL NA Hydrobin/ Settling NA NA NA Hydrobin Overflow / Pond Influent 

M1 Miller APC AL SPD‐4 Settling NA NA NA

End of Economizer Ash Sluice Pipe /

Pond Influent 

M1 Miller APC AL SPD‐4 Settling NA NA NA Ash Pond ‐ Middle of Pond 

M1 Miller APC AL SPD‐4 NA Not available 593 million 5 Ash Pond Near Effluent 

G1 Gorgas APC AL NA NA NA NA NA Source Water 

G1 Gorgas APC AL SPD‐6 Settling NA NA NA End of BA Sluice Pipe / Pond Influen

G1 Gorgas APC AL SPD‐6 Settling NA NA NA End of FA Sluice Pipe / Pond Influen

G1 Gorgas APC AL SPD‐6 Settling NA NA NA Ash Pond ‐ Middle of Pond 

G1 Gorgas APC AL SPD‐6 Settling Not available 468 million 3+ Ash Pond Near Effluent 

928

14934599

771

Doc ID # 51044784 
* All information in columns labeled "CBI" is confidential business information

Attachment 2

Sulfides Data Summary Sheet

Plant ID CBI Plant Name

A1 Kyger Creek

A1 Kyger CreekA1 Kyger CreekA1 Kyger Creek

E1 EC GastonE1 EC GastonE1 EC GastonE1 EC GastonE1 EC Gaston

M1 Miller

M1 MillerM1 MillerM1 MillerM1 Miller

G1 GorgasG1 GorgasG1 GorgasG1 GorgasG1 Gorgas

For effluent samples, identify wastestreams that contribute

to ash pond discharge and percent contribution

CBI

Average Annual

Bottom Ash Sluice

Water Flow Rate

(MGY)

CBI

Source water

used for Sluicing

Source Water ‐ 

Sampling Location

Source Water

Sampling

Location

Upstream of

Plant

Discharge(s)?

Source W

Treated P

Use in Slu

NA 791 MGY Ohio River NA NA NA 

BA sluice water is the only wastestream that discharges into

the bottom ash pond complex. NA Ohio River NA NA NA 

NA NA Ohio River NA NA NA 

NA NA Ohio River Intake at river NA Non

NA NA Coosa River Intake at river Yes Non

NA 389 MGY Coosa River NA NA NA 

NA

2474 MGY (Flyash

Sluice Water) Coosa River NA NA NA 

NA NA Coosa River NA NA NA 

Flyash sluice water (74%), bottom ash sluice water (8%),

cooling water (10%), FGD wastewater (1%), coal pile runoff

(1%), stormwater (5%), other (1%)

NA Coosa River NA NA NA 

NA NA

Mulberry Fork

River is used for

makeup

Service water tap after

the service water pond NA

Service 

holding 

NA 445 MGY Ash pond water NA NA NA

NA

476 MGY (Economizer

Ash Sluice Water) Ash pond water NA NA NA

NA NA Ash pond water NA NA NA

Flyash sluice water (38.5%), bottom ash sluice water (29%),

cooling water (5%), FGD wastewater (8.4%), coal pile runoff

(0.7%), leachate (2%), other (16.3%)

NA Ash pond water NA NA NA

NA NA Warrior River Intake at river Yes Non

NA 450 MGY Warrior River NA NA NA 

NA

1812 MGY (Flyash

Sluice Water) Warrior River NA NA NA 

NA NA Warrior River NA NA NA 

Flyash sluice water (21%), bottom ash sluice water (21%), FGD

wastewater (1%), coal pile runoff (1%), stormwater (13%),

other (43%)

NA Warrior River NA NA NA 

Doc ID # 51044784