We Energies 

231 W. Michigan St.

Milwaukee, WI 53203 

www.we-energies.com

May 18, 2010 

Mr. Ronald P. Jordan 

U. S. EPA 

Engineering & Analysis Division (4303T) 

Ariel Rios Building 

1200 Pennsylvania Avenue, N.W. 

Washington, DC 20460 

RE: Draft Sampling Plan for the Pleasant Prairie Power Plant, dated May 3, 2010 

Dear Ron: 

We Energies appreciates this opportunity to comment on the draft Sampling Plan (“Plan”) for our 

Pleasant Prairie Power Plant (“P4”), dated May 3, 2010. We are conveying comments to you in 

the following two ways: 

1) Our specific edits, including answers to questions embedded in the Plan text, are provided 

in the Word file being e-mailed to you and those at the Eastern Research Group (ERG) 

who are involved in this project. 

2) Through this letter, we are endorsing, with some very limited exceptions, the comments 

submitted by Duke Energy on April 20, 2010 for the Belews Creek facility. 

Below are topics covered in the Duke letter about which We Energies has some additional insight 

or point of emphasis. The items below have the same number as was used by Duke. 

1. Four Days of Sampling Will Not Capture the Variability of the System

We have not evaluated how many sampling events would be required to properly capture the 

variability of the discharge from a system such as a wet flue gas desulfurization (FGD) treatment 

facility. Therefore, we do not have specific recommendations about what the sampling duration, 

interval, frequency and intensity would need to be to properly capture this variability.1

Nevertheless, an appropriate sampling duration is going to be greater than one week to capture the 

variability of the operation of a wet FGD system like the one at P4 as the residence time for this 

system is much greater than the four day duration of EPA’s program. 

The lowest cost means to increase the size of the effluent data set for any system that EPA plans to 

sample would be to use data submitted on NPDES permit applications or discharge monitoring 

reports. Sampling conducted for applications or permit required monitoring is done using EPA 

 

1 Sample Duration – Is the temporal extent of the sampling period (e.g., one year). Sampling Interval – Is the 

length of the time period during which one or more sampling events takes place (e.g., weekly); Sampling Frequency

is the number of days in an interval that sampling takes place (e.g., daily); and Sampling Intensity is the number of 

sampling events during each day that is sampled (i.e., 4 samples taken over a 24-hr period). 
Mr. Ronald P. Jordan 

May 18, 2010 

Page 2 

approved methods throughout the year. Such an approach is another low cost alternative to 

reliably increase the size of a data set beyond what was identified in Duke’s comment letter. 

2. The Frequency of Field Blanks for Low-Level Mercury Do Not Meet Method 

Requirements 

See the discussion for the following section. 

3. Frequency of Field Blanks for Metals Is Not Sufficient At the Effluent Locations 

Probably the most compelling reason to increase the frequency of the field blanks is found in the 

last sentence of comment no. 2 on page 3 of the Duke letter that has been restated below. This 

comment equally applies to both comments no. 2 and no. 3. 

If only a single clean Hg field blank is collected at each sampling point, then EPA 

runs the risk of having a substantial number of low-level Hg data points from each 

SP being invalidated and judged unusable due to contamination bias if Hg is 

detected in the single associated field blank. 

4. Split Samples Should Be Collected for Mercury and Total Cyanide Grab Samples 

The whole purpose of splitting samples with another party is to validate the work of the other. 

Therefore, samples need to be split in a manner that eliminates the potential that some other 

variable could influence the results (i.e., sequential samples taken minutes later when a condition 

may have possibly changed). There are acceptable multi-pour techniques that can, and should, be 

applied to split grab samples thereby eliminating the potential concern about whether analytical 

result differences are actually due to operational variability or some other factor. We Energies 

believes that split samples are critically important for both mercury and total cyanide analyses. 

8. Data Accuracy and Usability Concerns 

To echo the concerns expressed by Duke, unless EPA and UWAG both share the results of the 

November 2009 split sample study, there will be no way of evaluating whether the proposed CRCICP-MS method is capable of producing accurate results. These results need to be mutually 

shared so that this analytical method can be properly validated. 

Sincerely, 

David M. Lee, P.E. 

Manager – Water Quality