UNITED STATES ENVIRONMENTAL PROTE C T I ON AGE N CY

WASHI N G TO N

, D

. C

. 204 6 0

Ms. Michalene Reilly Manager

, Environmenta l Services **March 10,**  **2014** OFFICE OF WATERHoosier Energy Rural E le ctric Cooperative
P.O. Box 908 Bloomington

, IN 47402-0908

Dear Ms. Reilly:

We received the comments submitted by Hoosier Energy Rural Electric Cooperative (Hoos ier ) regarding EP A ' s proposed effluent limitations guidelines and standards ( ELGs) for

t h e steam electric power generating point source category (78 FR 34432). We ar e writing to

you because we have concluded that based on review of the Hoosier comme n ts and the Utility Water Act Group (UWA G) comm ent s , which Hoo s i e r endorses, additional
information is either need ed or would be useful in evaluating the comments with respect to fly ash and bottom ash wastewater characterization. In some cases , clarification is n ee ded in order to properly interpret

, vali date

, and evaluate the ash data s ubmitted. We are therefore asking that you provide the
information described b e l ow in order to ens ure that the Agency appropriately considers

your s ubmission.

As yo u are aware , E PA 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 lett er be received by EPA 

### no later than March 31,2014.

Information Requested from th e Frank E. Ratts Generating Stat ion

Hoosier E nergy provided data on 32 sampl es of bottom ash and fly ash pond effluent
collected between Septembe r 2008 and December 2009 at the Frank E. Ratts Generating
Stat ion for a Reasonable P otential to Exceed analysis of nine paramet e r s for a permit
renewal. A dditionall y , Hoosier provided data on 29 samp les of fly ash pond effluent and 28 samples of bottom ash pond effluent collected for mercury analysis.

1

. Pl ease provide any fly ash or bottom ash transport water data ( i.e

. , wastewater samples of the tr ansport water prior to commingling or mixing with other
wastestreams in the ash pond). Please provide paired source water sam ple data whe re available. We only have effluent da ta for ash pond discharges. 2. Please provide any fly ash and/or bottom ash pond effluent data collected s ince

Dec embe r 2009

. Attached.
3

. For the pond effluent data supp l ied in your comment lette r , as well as any addit i ona l pond effluent data supplied in response to this request, please provide the Pond/Impoundm e n t Un i t IDs (e.g., SPD-2) from the 2009 EPA questionnaire for the ponds from which

bottom ash and fly ash pond effluent samples were collec t ed

. Bottom Ash Pond is SPD-1 and the Fly Ash Pond is SPD-2 (Only two active ponds)I n te rne t Address (URL) • http ./lwww

epa

. gov R ecyc l e d / Re

c y c lable • Pnnted with Veget a ble Oil Base d Inks on 100% Postconsume r

. Process Chlorine Free Recycled Paper

Please pro v ide the dimensions for each pond, including surface area, depth, and residence
time. We do not have the dimensions of the ponds. The surface area of SPD-1 (bottom ash pond) is estimated to be 283,140 ft 2 . The surface area of SPD-2 (fly ash pond) is estimated to be 870,000 ft 2 . The depths and residence times are unknown; the ponds were designed to have average depths of 8 ft. (bottom ash) and 10 ft. (fly ash) for the ponds. The depths today would be considerably less.

Also, please identify what other wastestreams flow into each impoundment and their

r e lative contributions. Bottom ash pond; 90% BA sluice water, 8% Coal pile runoff, 1% Air Preheater Wash water (non-chemical meta l cleaning wastes) and 1% stormwater. Fly ash pond; 88% FA sluice water, 1% non-chemical metal cl eaning wastes 1% stormwater and 10% Other wastewater (boile r blowdown, reverse os mosis reject water, green sand filter backwash).

4. For any fly ash or bottom ash transport water data co llected

, plea se provide the Pond/ Impoundment Unit ID (e.g., SPD-2) for the pond which fly ash or bottom ash transport water sampled would enter. Please provide the dimensions for this pond including surface area, depth, and residence time. Also, please identify what other wastestreams flow into this impoundment and their relative contributions. See answers to question 3 (there is only one active bottom ash and one active fly ash pond at the Ratts Station).
5. Describe any solids separa tion processes and treatment procedures associated with fly ash and/or bottom ash transport water or pond effluent. Fo r 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 th e sample location. Settling in the ash ponds is the only solid separation process. Settling occurs upstream of effluent sampling.

6. Please identify what chemicals are added to th e wastewater upstream of t he sample
location or to the samp le during settling. None.

7. Please provide a more detailed description of the sampling method beyond "collected in
accordance w ith Method 1 669." Low level mercury sampling is conducted by a c o n t r a c t l a b o r a t o r y in accordance with Method 1669; “ c l e a n h a n d s / d i r t y hands” technique. I have asked the laboratory to provide a detailed description. Specify th e location of the pond effluent samples provide d ( e .g. , collected from pond
overflow weir prior to entering discharge canal) and whether each sample was a grab or composite sample. Additionally

, provide duration and frequency information for all composite sampling (e.g., 24

- hour composite collected ever y h our). The bottom ash pond effluent samples are collected from a manhole immediately downstream of the pond’s discharge point, no other wa ter combines with the pond effluent. The fly ash pond samples are taken from the discha rge pipe prior to entering a ditch that fl ows to the White River. All samples were grab samples.
8. How often is fly ash and bottom ash slu i ced at the plant (provide both the daily frequency
and duration for typical operating practic es)? Both bottom ash and fly ash is sluiced daily. Bottom ash is sluiced an average of 8 hours per day and fly ash is sluiced an average of 16 hours per day.P l ease identify w h ether source water is continuously transferred to the ash pond even
when fly ash and/or bottom ash are not being sluiced. N o , source water is not continuously transferred to the ash pond when fly ash and/or bottom ash are not being
sluiced. Indicate whether samples were collected during periods when the bottom ash is

not sluiced (i.e., source water is flowing through the s l uice pipe ). Samples were taken at the discharge of the ash ponds and sampling was done dur ing the first shift when it is likely that ash was being sluice d, but it is possible some samples were taken when ash was not being sluiced.

9. Please indicate whether any significant discharges lie upstream of the plant's White Ri ver intake that may cont ribute to background levels of pollutants (i.e., mining/ excavation activities, facilities which discharge into the river ). There are numerous significant dischargers upstream of the in take including municipal wast ewater treatment plants for the cities of Anderson, Muncie , Indianapolis, Bloomington, Bedford and several others. These plants have major indus trial dischargers to their sy stems. Three coal-fired power plants also discharge into the White Rive r upstream of the Ratts intake. The 2,000 megawatt Indianapolis Power & Light Petersburg Station is only 0.5 miles upstream. 10. Please provide additional details regarding the so urce water sampling locations:

a. Please specify the loca tion of the source wa t er samples provid e d and indicate whether the plant discharge i s upstr ea m or downstream of intak e water location (i.e., does a ny of the plant 's effluent contribute to intake water ) ? Source water samples are taken from the ri ver water pumps at the intake. This is upstream of the plant discharges; none of the plant's effluent contributes to intake water. b. Does the plant treat the intake water prior to use in the fly ash or bottom ash sluicing systems? No. If so, ho w is the intake water treated?

c. Doe s the plant recycle any process wastewater for use in the fly ash and / or bottom
ash s lui cing system. This includ es any recycling of the pond effluent from the ash ponds. If so, how? No. 11. Please provide the associated T SS concentration for the source water

, fly ash, and bottom

ash samples. TSS analysis was not done on the samp les; they were collected for RPE analysis for metals and sulfates. TSS analysis is done weekly for both bottom ash and fly ash pond effluents. Bottom ash pond samples aver aged 8.0 mg/l TSS with a maximum daily value of 43.6 mg/l and fly ash pond samples averaged 11.1 mg/l w ith a maximum daily value of 44.4 mg/l during the last permit cy cle (data taken from NPDES Permit Renewal Application filed on 2 March 2010). 12. Please provide the flow rate of the wast ewa ter at the time of sampling, as well as the average annual bottom ash discharge flow rate. Sluice rates are provided with additional analytical results, effluent flow is not directly monitored from the ponds. Please also provide s luice flow for all mercury re su lt s presented in Attachment

2 of your comment l etter. Done.
13. Describe any atypical operations occurring at the plant at the t im e of any sampli ng (e.g.,

test bum of new coal). There were no test burns of new coal during sampling. Testing of several sorbents for air pollution control injection (direct injection of sorbents into flue gas) did occur during some wastewater sampling. In 2008 during a 19 day period in February – March, a 19 day period in April and an 8 day period in May tests were done with limestone, hydrated lime and lime kiln dust injection respectfully. From November 14 – 15 in 2011 tests were done with dry sorbent injections of Trona (sodium sesquicarbonate), sodium carbonate
and activated carbon.14. What basis was u se d for determination of atypical hi gh pollutant levels from the
White River w hi ch were excl uded from calculations? Only a few samples were recommended for exclusion due to high source water levels of pollutants. On 11/4/08 the river water levels of arsenic, chromium and zinc were 114, 165 and 163 ug/L respectfully. On 7/7/09 arsenic was 865 ug/L and chromium was 57 ug/L. This compares to river water levels of BDL (7 ug/L) arsenic, 3.8 ug/L chromium and 40 ug/L zinc without these high samples. In the additional data provided, on 11/17/2011 it is obvious that high source water levels of lead caused high levels of lead in the pond discharges. The same effect occurred on 11/18/2011 for lead and copper. It is apparent that elevated levels of pollutants in the source water can affect discharge levels.

Pl ease indi cate w hat ma y have caused such high levels in the White Ri ver wa t e r

co lumn durin g these sampli n g p e r i ods

. As you can see in the answer to question 9, there is no lack of si gnificant dischargers to the White River upstream of the Ratts Station. Any of them or ot hers could cause elevated levels of pollutants in the river.
15. What basis was used for d e termination of im p roper h a ndlin g or analyses of the water

sa mpl es by the co nt racto rs which were excluded from ca l c u l at i o n s? It was not
im proper handling or analyses of the water samples by laboratory contractors that lead to excluding two results. It was heavy equipment contractors doing dredging work in the ash ponds that we believe lead to high mercury levels. These were the only times that dredgi ng activities occurred during effluent sampling and the affects were pro nounced. In August 2007 the mercury concentration in the fly ash pond samp le was 16.4 ng/L versus an average concentration of 2.76 ng/L w/o that sample. In October 2007 the mercury concentration in the bottom ash pond samp le was 10.46 ng/L versus an average of 1.52 ng/L w/o that sample.

Inform ation R equested from th e Mero m Generating Sta ti on ( Pla n t ID 03719)

Plea se pr ov ide the same data and s upportin g d eta il s as detail e d above for the Merom Gene r a t i n g Station. The Merom Station has a dry fl y ash handling system and us es dewatering bins with
water recirculation for bottom ash handling. Although the bo ttom ash handling system will discharge wastewater, it goes to a wastewater treatment plant not to a pond, and we have not sampled this wastestream separately.

Attachme nt 1 provi de s guidelines for sub m i tt in g a n a l y ti cal data (and s upplemen t al

i nformat i o n) under thi s request.

We app r ec iate you r help i n pro v idin g the information de scr ibed above in a timely manner. I f you h ave any questions

, pl ease do not h es i tate t o call m e at 202-5 66-
1003

.

Sincerely

Eng i neering and An a l ys i s Divi s i on