### MEMORANDUM

TO: Steam Electric Rulemaking Record

FROM: Ryan Novak and Deb Bartram , ERG

DATE: 30 September 2015

SUBJECT: Steam Electric Effluent Guidelines Analytical Dataset

– UWAG Bottom Ash

Data

– Final Deliverable

1. I NTRODUCTION /B ACKGROUND

EPA used data collected during the detailed study, industry

- supplied data, and publicly available data sources, including data received during public comment, to develop the analytical dataset used to characterize bottom ash transport water and estimate the industry’s pollutant loadings. This memorandum describes the evaluation and use of data submitted by the Utility Water Act Group (UWAG)

.

Throughout the development of the effluent limitations guidelines and standards (ELGs)

, EPA c oordinated with UWAG, an industry trade association representing 198 individual energy companies and three trade associations of energy companies. As part of this coordination, UWAG provided EPA w ith several bottom ash transport water analytical datasets for EPA’s

consideration and use in the characterization of bottom ash transport water. The remainder of this

section further describe s these bottom ash transport water data submissions.

1.1 Form 2C Per mit Application Data

During the detailed study of the steam electric power generating industry

, EPA

coordinated efforts with UWAG to create a database of selected National Pollutant Discharge Elimination System (NPDES) Form 2C data from UWAG’s member comp anies [UWAG, 2008]

. The NPDES Form 2C database , compiled and generated by UWAG and provided to EPA,

contains information about the outfalls from 86 coal

- fired power plants that discharge FGD, ash handling, or coal pile runoff wastestream s. All source water concentration data and plant outfall data were reviewed for possible inclusion in the ash pollutants of concern and loadings analyses.

EPA used information collected in Parts A and D of the Questionnaire for the Steam Electric Power Generating Effluent G uidelines (Steam Electric Survey) [U.S. EPA, 2010] to calculate the percent contribution of the ash transport water to the total outfall flow rate. EPA evaluated all references used to characterize ash impoundment discharge for the final rule and reviewed all data against the ash data acceptance criteria for the final rule outlined in Attachment

1 of this memorandum

. EPA i ncluded Form 2C data meeting all of these acceptance criteria in

the bottom ash transport water pollutants of concern and pollutant loadings analyses for the final

rule

.Memorandum

30 September 2015 Page 2

1.2 Data Submitted During Public Comment

As part of its public comment submission in September 2013 , UWAG provided a t able presenting bottom ash transport water data for samples collected from 21 plants [UWAG,

2013 a ]. The UWAG samples date from 2001 to 2013, with samples from 17 of the plants

collected between 2010 and 2013. In some cases, UWAG also provided source water data collected on the same sample day as the bottom ash transport water samples. As part of their public comment submission, UWAG also provided a report prepared by URS Corporation with 2013 sampling data for sulfides (as wel l as some other parameters) at nine plants

. UWAG masked the identity of all plants included in the bottom ash transport water database and sulfides
report.

On December 30, 2013, EPA requested additional information and clarification from UWAG in order to properly interpret, validate, a nd evaluate the data to determine if these data met EPA’s acceptance criteria for inclusion in the pollutant s of concern and pollutant loadings analyses. Specifically, EPA requested UWAG to provide more information about the identity of the sampled plants, the sample collection location and methods used, the selection criteria used by UWAG when developing their dataset, information on how nondete ct values were handled when calculating average concentrations, total suspended solids results associated with th e samples, and other plant

- specific information. In this request, EPA reminded UWAG that the Agency is operating with a deadline for taking final action on the steam electric ELGs and thus requested “additional information you provide in response to this l etter be received by EPA no later than January 24, 2014 ” [U.S. EPA, 2013]

.

UWAG did not respond to EPA’s December 2013 information request until August 4, 2014, more than six months after the EPA deadline. Although much later than the deadline, EPA

was a ble to fully take these data into account for the analyses and evaluate d the data submitted by UWAG against the acceptance criteria listed in Attachment 1 of this memorandum

. Consistent with EPA’s ash transport water acceptance criteria [ERG, 2015 b ]

, E PA u sed the data submitted by UWAG in the loadings analysis unless :

 Ef fluent from the ash impoundment sampled was comprised of less than 75 percent ash transport water by volume

.

 Data were duplicative of other data accepted in the analytical database

.

 Plants were not identified

. For such plants , EPA could not confirm whether the samples met all the acceptance criteria because it did not have sufficient information about the sources and volumes of wastewater managed by the impoundment ( i.e.

, EPA could not veri fy that the effluent to the ash impoundment sampled was at least 75 percent ash transport water). Additionally, the lack of plant identification precluded EPA from evaluating whether the UWAG data were for impoundments already included in EPA’s Steam Elect ric Analytical Database.

 Samples did not represent actual effluent from an impoundment

. EPA excluded data submitted by UWAG that attempt ed to simulate impoundment effluent, using samplesMemorandum

30 September 2015 Page 3

that were collected prior to the ash pond and settled in a sampling c ontainer prior to

analysis for a subset of the plants [UWAG, 2013b ; UWAG, 2014a ]

. 1

Where data were confirmed to represent ash impoundment effluent samples and the ash contribution was at least 75 percent of the contributio n by volume to the impoundment , EPA

included these data in the ash impoundment effluent concentrations data set and further reviewed the data against the acceptance criteria

. EPA determined that the “simulated effluent” data were not wholly representative of ash impoundment discharges ; therefore, t hese data were instead used in a sensitivity analysis. The Incremental Costs and Pollutant Removals for the Final Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category report [ERG. 2015c] f urther describes the use of data from UWAG’s public comment submission in the loadings analyses and sensitivity analyses and the results of these analyses.

1.3 November 2014 Bottom Ash Data

At UWAG’s request, o n September 10 , 2014, EPA met with representatives from UWAG

to discuss the use of the bottom ash transport water data submitted by UWAG in public

comment s

. During this meeting, UWAG indicated that it had collected additional bottom ash
transport water characterization data. EPA stated that no further dat a were needed for EPA’s evaluation of bottom ash transport water [U.S. EPA, 2014].

On November 25, 2014, more than two months following the meeting with EPA on September 10, 2014, UWAG sent additional bottom ash transport water d a ta and asked EPA to
consi der it for the final steam electric ELGs [UWAG, 2014b ]

. 2 The late data included bottom ash transport water characterization data collected from six steam electric power plants. UWAG provided plant information sheets containing background and operational data regarding each of the plants sampled, analytical laboratory and quality control documentation for each sample, and the results of UWAG’s analysis of the results.

By November 25, 2014, EPA had already completed analysis of available ash

characterization data for use in the rulemaking

, completed development of the Stea m Electric Analytical Database [ERG, 2015a] , and finalized the ash loadings model used t o generate pollutant loadings estimates

. Therefore, EPA did not incorporate UWAG’s Nov ember 2014 data

into the Ash Data Review Matrix, the pollutants of concern analyses, or official loadings analysis [ERG, 2015b] . However, EPA did conduct a sensitivity analysis of the late data that were known to meet EPA’s acceptance criteria , as describe d further in Section 2

.

1 UWAG presented a comparison of settled sluice pipe samples to near

- effluent discharge point samples at each of the six plants sampled as part of the November 2014 submission. UWAG acknowledge that “whether viewed from the individual facility perspective o r as averaged across the six facilities, it is clear that the settled bottom ash sluice pipe samples substantially overestimate bottom ash effluent pollutant loadings” [UWAG 2014b].

2 These data were received 10 months after the January 2014 deadline estab lished by EPA’s December 30, 2013 letter. This was 14 months after the September 2013 close of the comment period for the proposed rule (more than 17 months after EPA publicly released a pre

- publication version of the Federal Register notice for the propos ed rule, soliciting additional pollutant characterization data).Memorandum

30 September 2015 Page 4

2. S ENSITIVITY A NALYSIS O F N OVEMBER 2014 UWAG D ATA

As described in Section 1 , EPA had sufficient time and information to evaluate and incorporate the Form 2C permit application data and bottom ash transport water data submitted in public comment s (including those data submitted by UWAG) into the ash transport water loadings analyses

. However, because UWAG’s late data w ere not sent to EPA until November 2014, and due to the additional time that would have been needed to fully evaluate the late data and revise the pollutant removal analyses and other related analyses for the ELGs ( e.g

. , environmental assessments), the late data could not be fully incorporate d into the loadings analyses. Never the less, EPA was able to conduct a n abbreviated evaluation of the late data to
determine the effect the late data could have on the loadings analyses [ERG, 2015d]

.

Based on the information submitted by UWAG with the November 2014 data and information submitted with previous data, EPA was able to confirm data from three of the six plants of UWAG’s November 2014 dataset came from impoundments that EPA had previously

confirmed that contained ash transport water contributions of at least 75 percent

, by volume (consistent with EPA’s acceptance criteria outlined in Attachment 1)

. 3 EPA elected to further

evaluate t he data from these three plants against the acceptance criteria, compile it and use it in a sensitivity analysis , in combination with the datasets used in the loadings calculations, to determine the impact these data could have if factored into the industry

- level bottom ash
transport water loadings.

EPA did not fully evaluate or include data fr om the remaining three plants represented in
UWAG’s November 2014 data set d ue to the unsolicited data being submitted well after the close of the comment period, limitations on time precluding EPA from evaluating whether the data met the acceptance criter ia , and because the bottom ash transport water data were determined to be comparable to the analytical dataset used by EPA.

The results of th e sensitivity analy sis are presented in Table 1

. This table illustrate s the impact of including these late data on the total baseline industry loadings , accounting for the Coal Combustion Residuals (CCR) rule

. 4

3 In prior submissions, UWAG provided information on K ammer , Kyger Creek Station, and Frank E. Ratts Generating Station that enabled EPA to readily ascertain the ash contribution for their impoundments.

4 EPA conducted this sensitivity analysis on a previous version of the pollutant load estimates. EPA recalculated the industry loadings for fly ash transport water and bottom ash transport water for the final rule and determined that the

dif ference between the final industry baseline loadings and the previous version of the pollutant loadings estimates is less than 1 percent in terms of pounds per year. Because the magnitude of this revision to the baseline loadings is very small and the sens itivity analyses also show little change in pollutant loadings/removals, EPA concluded that it was not necessary to update the sensitivity analysis with the revised baseline loadings because they would still show that there would be little change in the po unds of pollutants in the baseline loadings or removals.Memorandum

30 September 2015 Page 5

Table 1

. S ensitivity Analysis Results for Total Industry L oadings Based on Inclusion of

Late Submission UWAG Data Excluding BOD, COD, TSS, and TDS

Sensitivity Analysis Total Industry Baseline Loadings

Pounds/Year Percent Difference (%)

Bottom Ash Transport Water Baseline Loadings 354,000,000 NA

Inclusion of Late Submission UWAG Bottom Ash Data a 347,000,000 (1.93%)

Source: ERG, 2015d; ERG, 2015e Note: Excludes loadings for pollutants not identified as POCs and for BOD, COD, TSS

, and TDS.

Note: Loadings are rounded to three significant figures. Note: EPA completed t his sensitivity analyses with a previous version of the ash analytical data set. Since the completion of this sensitivity analysis, EPA recalculated the industry loadings for fly ash t ransport water and bottom ash transport water and determined they are less than 1 percent different in terms of pounds per year for both waste streams. EPA determined that this 1 percent reduction in loadings, coupled with the approximately 2 percent chang e from inclusion of the late submission UWAG bottom ash data, was not significant enough to warrant reanalysis and the results of the sensitivity analysis would be comparable to the analysis presented.

a

– EPA included results from three plants from the No vember 2014 data set where EPA had previously confirmed

those ash contributions are at least 75 percent of the contribution , by volume, to the impoundment.

The sensitivity analysis demonstrates that including UWAG’s November 2014 data

would have little impact on both the unweighted (pounds/year) pollutant loadings/removal estimates and other related analyses. Including the subset of the November 2014 data decreased the estimated unweighted pollutant loadings for bottom ash transport water by approximatel y 2
percent

. 5 Because of the very small impact on bottom ash transport water loadings associated

with this sample of late data, EPA concluded that the late data would not have a significant impact on the overall loadings , pollutant removal estimates, and related analyses for purposes of

the final steam electric ELGs

.

3. R EFERENCES

1. ERG . 2015 a

. Eastern Research Group, Inc. Analytical Database for Final Rule. (30 September). DCN SE05359

.

2. ERG. 2015 b . Eastern Research Group, Inc

. “ Ash Analytical Data Review

Memora ndum. ” (30 September). DCN SE05567.

5 Error! Reference source not found. shows that including the November 2014 data reduces the estimated pollutant loadings that take the CCR rule into account by less than 2 percent . EPA also estimated pollutant loadings using an alternative approach that takes the effect of the Clean Power Plan (CPP) into account (see the Incremental Costs and Pollutant Removals for Final Effluent Limitation Guidelines and Standards for the Steam Electric Power Generating Point Source Category [E RG, 2015c] ). Because the same pollutant concentration datasets are used for both sets of pollutant loadings/reduction estimates, the estimated pollutant loadings that take the CPP into account would be equally affected by incorporating the November 2014 da ta ( i.e. , unwe ighted loadings reduced by less than

2 percent ).Memorandum

30 September 2015 Page 6

3. ERG. 2015 c . Eastern Research Group, Inc. Incremental Costs and Pollutant Removals for the Final Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category . ( 30 September ). DCN SE05851

.

4. ERG. 2015d. Eastern Research Group, Inc. “Draft Ash Loadings Model, Accounting for

CCR

– UWAG Late Submission Sensitivity Analysis.” (30 September). DCN SE05625.

5. ERG. 2015e. Eastern Research Group, Inc. “Draft Ash Loadings Model, Accounting f or CCR

– Sensitivity Analysis Comparison.” (30 September). DCN SE0 6 4 18.

6. U.S. EPA. 2010. U.S. Environmental Protection Agency. Questionnaire for the Steam Electric Power Generating Effluent Guidelines . OMB Approval Number: 2040

- 0281. Washington, DC. (2 June ). DCN SE00402

- SE 00402A09.

7. U.S. EPA. 2013. U.S. Environmental Protection Agency. Post Proposal Data Request to

UWAG

– Bottom Ash Data Submitted in Public Comment. ( 30 December). DCN

SE04711.

8. U.S. EPA. 2014. U.S. Environmental Protection Agency. Meeting No tes for the Steam Electric Rulemaking Record, September 10, 2014 Meeting with Utility Water Act Group (UWAG) Regarding Proposed Steam Electric ELGS . ( 10 September). DCN SE 05578

.

9. UWAG . 2008. Utility Water Act Group. UWAG Form 2C Effluent Guidelines Database. (30 June). DCNs SE02918 and SE02918A1.

10. UWAG . 2013 a

. Utility Water Act Group. Comments on EPA’s Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category. (7 June)

. EPA

- HQ

- OW

- 2009

- 0819

- 465 5.

11. UWAG . 2013 b

. Utility Water Act Group. UWAG Bottom Ash Transport Water Sampling Protocol

. DCN SE 043 60 A22

.

12. UWAG . 2014a. Utility Water Act Group. UWAG Response to Post Proposal Information Request. (1 August). DCN SE04717.

13. UWAG . 2014b. Utility Water Act Gr oup. Additional Bottom ash Transport Water Data. (25 November). DCN SE05597.Memorandum

30 September 2015

Attachment 1

Attachment 1. Ash Transport Water Acceptance Criteria for Use of Data in Ash Loadings Analysis

ERG used the following data acceptance criteria to review and evaluate analytical data used to characterize ash transport water discharged from surface impoundments. Each dataset was specifically reviewed and flagged as acceptable for EPA’s ash effluent lo adings calculations based on the following:

 Sample locations must be unambiguous and clearly described such that it can be categorized by type (e.g., bottom ash impoundment effluent rather than impoundment effluent with no further definition) and level of treatment (e.g., untreated, partially treated).

 Sample must comprise at least 75% by volume ash transport water.

 Sample must be representative of actual ash impoundment effluent (not simulated effluent).

 Analytical data must represent individual sample r esults or plant

- level average sample concentrations rather than average results representing multiple plants.

 For biphasic samples (i.e., those with solids content >1%), sample analysis must provide results for both phases.

 Data must not be from an ash set tling test conducted in a column (i.e., a simulated sample of partially treated wastewater).

 Sample must be representative of full

- scale, typical plant operations.

 Sample analysis must be completed using accepted analytical methods

. 6

 Data must not be dupli cative of other accepted data. 7

 Sample data must provide sufficient information to identify units.

 Non

- detect results were not accepted if no limit (e.g., DL, QL) was provided.

 Sample results must represent total (i.e., dissolved results were not accepted except for TDS).

6 Methods prescribed in 40 CFR Part 136 ; Methods 200.7, 200.8

, or 1638 for Metals analysis ; and Methods 1631 and/or 245.7 for Mercury (Method 245.1 is not acceptable because it is not sufficie ntly sensitive to measure concentrations of mercury in impoundment effluent ).

7 Duplicate data were submitted by associations representing individual plants (e.g., UWAG). In such cases, EPA

used the data submitted by the individual plant

.