UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

Elizabeth E. Aldridge 

Hunton & Williams LLP 

951 East Byrd Street 

Richmond, VA 23219-4074 

Dear Ms. Aldridge, 

DEC 3 0 2013 

OFFICE OF WATER 

We received the comments you submitted on behalf of the Utility Water Act Group 

(UW AG) regarding EPA's proposed effluent limitations guidelines and standards (ELGs) for the 

steam electric power generating point source category (78 FR 34432). We are writing to you 

because we have concluded that additional information is either needed or would be useful in 

evaluating your comments with respect to fly ash and bottom ash. In some cases, clarification is 

needed in order to properly interpret, validate, and evaluate the ash data submitted along with 

your comments. We are therefore asking that you provide the information described below in 

order to ensure that the Agency appropriately considers your submission. 

As you are aware, EPA is operating with a deadline for taking final action on the steam 

electric ELGs. We are thus requesting that any additional information you provide in response to 

this letter be received by EPA no later than January 24, 2014. 

The following requests and questions pertain to data provided in Attachment 7 of 

UWAG's comments. 

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., SPD2) for the sampled pond, as reported in the Questionnaire for the Steam Electric Effluent 

Guidelines. 

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, please identify what chemicals are 

added to the wastewater upstream of the sample location. 

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

If UW AG 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 UW AG that were 

not included in UWAG's comments to EPA? If so, why were these data excluded? 

Internet Address (URL) • http://www epa.gov 

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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? 

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. 

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. 

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

a. Source water 

1. 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). 

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

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

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

sluicing system. If so, how? 

b. Bottom ash transport water 

1. 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). 

11. 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. 

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. 

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). 

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

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

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. 

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. 

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 approach described in Note 1 is comparable to the actual 

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performance expected in the surface impoundments at the plants for which the samples 

represent. 

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 following requests and questions pertain to data provided in Attachment 5 of 

UWAG's comments. 

I. 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., SPD2) for the sampled pond, as reported in the Questionnaire for the Steam Electric Effluent 

Guidelines. 

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. 

3. From which plants/companies did UW AG request sulfide characterization data? What 

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

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

samples were collected? 

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

a. Source water 

1. 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). 

u. Is intake water treated prior to use in the bottom ash sluicing system? If 

so, please describe the treatment process. 

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

sluicing system? If so, how? 

b. Bottom ash transport water 

1. Please specify the location of the bottom ash sample provided for Plants 

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

n. 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. 

u1. 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. 

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

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

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. 

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

Table l. 

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We appreciate your help in providing the information described above in a timely 

manner. If you have any questions, please do not hesitate to call me at (202) 566-1755. 

Sincerely, 

f)Jf.i- {;/ 

J ezebele Alicea-Virella 

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