0Good Morning Joe, 

Thank you for submitting additional data from Hatfield’s Ferry. We believe that this will 

be helpful for evaluating comments regarding treatment of FGD wastewater. We would 

like to ask you some follow-up questions to ensure that we understand the submitted data. 

We understand that it may be difficult to locate some records because of the 

deactivation of the facility, however we would appreciate any input that you can offer. 

These are the specific questions we would appreciate your input on regarding the Excel 

Spreadsheet that you sent us a couple of weeks ago. 

1. What method was used for Arsenic in column D (AS - Arsenic) and Column E 

(HGTGEO - Mercury, Trace, Geochemical Labs)? The MDL is included on the spreadsheet, 

but we don't know what the quantitation limit and the reporting limit are. 

Arsenic results in column D were analyzed by 200.7 (ICP). The mercury data from 

Geochemical Labs was by 245.7. Mercury results presented in Columns F & G were also 

analyzed by Geochemical Labs. Note that Column G is a duplicate of Column F – see 

explanation to question #4 below. The West Virginia Department of Environmental 

Protection (WVDEP) requires us to report down to the MDL on our Discharge Monitoring 

Reports (DMRs). To be consistent in our reporting across all facilities regardless of 

location (State), Allegheny’s and now FirstEnergy’s labs report their data to the MDL on 

our DMRs. The data provided in this spreadsheet was submitted to the PADEP on 

Hatfield’s DMRs. With that being said, the quantitation level for column D arsenic results 

from FirstEnergy’s lab is 0.03 mg/L and the mercury quantitation level for Geochemical is 

0.03 μg/L. 

2. In Column D (AS - Arsenic) one value is reported as <MDL and several are 

reported as 0. What exactly does a reported value of "0" mean? Were these samples also 

below the MDL? Does this mean the sample was a nondetect? A zero means the analysis 

returned a result below the MDL. Initially, our Laboratory Information Management 

System (LIMS) software would only accept numeric entries. To avoid error messages 

when entering data below the MDL, numeric values less than the MDL were entered into 

the database. Sometimes zeros were entered and other times actual values, values below 

the MDL, from the instrument were entered into the database. Any value entered that 

was below the MDL returned a less than the MDL value on the DMR. The software has 

since progressed and can now handle alpha entries such as <MDL. On the DMR, the actual 

numeric value for the MDL is returned (e.g. < 0.03 mg/L). Also, in order to calculate 

averages, values that returned a <MDL may have been converted on the spreadsheet to 

zero (0), per EPA’s guidance for calculating averages when some of the data is below the 

MDL.

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3. In Column E (HGTGEO - Mercury, Trace, Geochemical Labs) several values are 

reported as 0. What exactly does a reported value of "0" mean? Were these samples also 

below the MDL? Does this mean the sample was a nondetect? Yes, see above explanation 

to question #2.

4. What is the difference between Column F and Column G, both of which are 

labeled Hg (245.7)? They are identical. Is the unit on Column G a typo? Yes. Should they 

both be ug/L? Yes! (The same numbers are reported in the two columns, but the units are 

different) Why is the sample from 9/17/2013 listed as below MDL in Column F and zero in 

Column G? This is a typo. Somehow when I transferred the data to the spreadsheet 

Column F was duplicated in Column G. Column F and G are identical and the units are in 

micrograms per liter (μg/L) for both columns. The mg/L listed in Column G is a typo. I 

suggest you delete Column G. The 9/17/2013 sample in Column G had the MDL converted 

to zero in order to calculate the average and obtain the proper sample count. In my hurry 

to get this to you by the deadline, I missed it. Sorry for the confusion! Also, since 

Geochemical Labs analyzed the data presented in Columns E & F and the only difference is 

that the data was pulled from two different LIMS because of the switchover from 

Allegheny to FirstEnergy, the columns could be combined into one dataset for mercury.

5. What is different about the samples reported between 7/7/2009 and 

11/29/2011 and 11/6/2012 and 12/10/2013? Allegheny’s Chemical Lab analyzed all of the 

arsenic samples between 7/7/2009 and 11/29/2011, while FirstEnergy’s Beta Lab analyzed 

arsenic samples from 11/6/2011 through 12/10/2013. Decommissioning Hatfield's Ferry 

only accounts for data acquired after 10/6/2013. The last generation at Hatfield 

occurred on 10/6/2013, but in order to drain the FGD system all water was directed 

through the FGD-WWTP and discharged via Internal Monitoring Point 306 (IMP-306). 

The samples from 11/6/2012 onwards do not have sample numbers. Was a different 

method or a different laboratory used? Allegheny and FirstEnergy used two different 

versions of the same LIMS software. The switchover occurred in November 2012. The 

search to pull data from Allegheny’s LIMS includes the Lab ID #, whereas, the search 

that pulls data from Beta’s LIMS does not. Are these values in different units? For 

arsenic, the units are the same. Allegheny’s lab only ran 245.1 for mercury, as does Beta 

Lab, so all of the mercury samples were sent out to Geochemical Labs for 245.7 analysis. 

Again, the reason the 245.7 results are presented in two different columns (Columns E & F 

– delete G) are because they were pulled from two different LIMS.

Thanks in advance for any advice you can offer, 

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