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 comm ent on the draft Sampling Plan (“Plan”) for our Pleasant Prairie Power Plant (“P4”), dated Ma y 3, 2010. We are conveying comments to you in the following two ways:

1) Our specific edits, including answers to questio ns 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 ha ve the same number as was used by Duke.

1. Four Days of Sampling Will Not Capt ure 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 a bout what the sampling duration, interval, frequency and intensity would need to be to properly captu re this variability. 1

Nevertheless, an appropriate sampling duration is goi ng to be greater than one week to capture the variability of the operation of a wet FGD system lik e the one at P4 as the residence time for this system is much greater than the f our day duration of EPA’s program.

The lowest cost means to increase the size of the e ffluent 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 th at sampling takes place (e.g., daily); and Sampling Intensity is the number of sampling events during each day that is sample d (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 a pproach is another low cost alternative to reliably increase the size of a data set beyond wh at 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 No t 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 numb er 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 Mer cury 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 resu lts (i.e., sequential samples take n 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 so me 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, unles s EPA and UWAG both share the results of the November 2009 split sample study, th ere will be no way of evaluating whether the proposed CRCICP-MS method is capable of producing accurate re sults. 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