Tetra Tech, Inc.

10306 Eaton Place, Suite 340

Fairfax, VA 22030

phone 703-385-6000

fax 703-385-6007

TO: Paul Shriner, EPA

FROM: Blaine Snyder, Hen

DATE: December 7, 2010

SUBJECT: Estimated costs for conducting entrainment monitoring 

Introduction

Tetra Tech was tasked with developing an estimate for

memo provides multiple examples 

support of 316(b) as a way to provide perspective on entrainment sampling costs

supports the use of a cost estimate of approximately $490,000 per facility per year

reasonable on a national scale, but site

exact study design, the site location, 

sampling, and other assumptions.

Examples

Example 1 

Tetra Tech (and one subcontractor) conducted entrainment sampling at “small 

in 2002 in support of Phase III Rule development.

River estuary, which represents relatively local travel

peak of the spawning/nursery season.

one week (4 days) during each of the two sampling events.

every 3 hours over the 24-hour period.

the total cost of the project was just over $600K.

impingement and entrainment sampling and design (and we used an experienced subcontractor), 

the sampling was local, and the total costs are 2002 dollars.

Example 2

We reviewed the costs provided in

MEMORANDUM

Paul Shriner, EPA

Blaine Snyder, Henry Latimer and Kelly Meadows

, 2010

Estimated costs for conducting entrainment monitoring 

Tetra Tech was tasked with developing an estimate for entrainment monitoring cost

multiple examples of monitoring cost estimates developed by Tetra Tech in 

provide perspective on entrainment sampling costs

supports the use of a cost estimate of approximately $490,000 per facility per year

reasonable on a national scale, but site-specific costs can vary significantly depending on the 

exact study design, the site location, the experience/expertise of the staff conducting the 

, and other assumptions.

Tetra Tech (and one subcontractor) conducted entrainment sampling at “small facilities” for EPA 

in 2002 in support of Phase III Rule development. We sampled at 6 facilities in the Delaware 

, which represents relatively local travel. Each facility was visited twice during the 

peak of the spawning/nursery season. We collected both entrainment and nearfield samples for 

one week (4 days) during each of the two sampling events. Each day consisted of sampling 

hour period. Our total number of samples was approximately 700, and 

the project was just over $600K. Keep in mind that we’re “experienced” in 

impingement and entrainment sampling and design (and we used an experienced subcontractor), 

the sampling was local, and the total costs are 2002 dollars.

costs provided in the Phase II NODA (2003) and the ICR Cost Analysis

entrainment monitoring costs. This 

developed by Tetra Tech in 

provide perspective on entrainment sampling costs and ultimately

supports the use of a cost estimate of approximately $490,000 per facility per year. This cost is 

ficantly depending on the 

of the staff conducting the 

facilities” for EPA 

We sampled at 6 facilities in the Delaware 

Each facility was visited twice during the 

collected both entrainment and nearfield samples for 

Each day consisted of sampling 

Our total number of samples was approximately 700, and 

Keep in mind that we’re “experienced” in 

impingement and entrainment sampling and design (and we used an experienced subcontractor), 

the Phase II NODA (2003) and the ICR Cost Analysis and 
attempted to extract only entrainment sampling, laboratory, analysis, and reporting costs. It 

appears that the sampling scheme proposed at the time was 3 years of sampling, 26 weeks each, 

with 5 samples per week, for a total of 390 entrainment samples per facility. It is not 

straightforward to extract the costs from the expansive spreadsheets, but it appears that the total 

annual cost per facility would be approximately $100K (or $300K for 3 years of sampling). This 

represents on-site entrainment sampling, using experienced personnel, and a 2003 dollar value.

Example 3 

We generated cost estimates for EPA in November 2009 based on entrainment study

assumptions discussed at that time: 100 sampling events per year; sampling once per week for 10 

months; sampling daily for the other 2 months; collecting 24-hour composite samples; and 

sampling at any/all waterbody types (excluding marine). We added the assumptions that all 

samples were truly entrainment samples, collected on-site at the facility (e.g., behind the screens) 

and did not include any nearfield samples, boat samples, and the like. Therefore, equipment 

costs (e.g., boats, nets, etc.) were not included as part of other direct costs. Three scenarios were 

considered, including: a) use of a non-local consultant (i.e., requiring travel to the sampling site); 

b) use of a local consultant; and c) “in-house” sampling (i.e., consultants would train facility

employees to do the work, resulting in labor costs that are near zero). Consideration of the three 

scenarios resulted in total costs of approximately $490K, $320K, and $100K per year, 

respectively, in 2009 dollars. (See Attachment A.)

Discussion

As noted above, several of the cost estimates presented here were derived on a national scale 

using very broad assumptions and may not be representative of site-specific costs for some 

facilities. Given the complexity of sampling, the lack of on-site or in-house experience, and the 

high level of expertise involved in conducting scientifically valid studies, we believe that most 

entrainment studies would be conducted by non-local consultants, resulting in the highest cost 

scenario presented in Example 3 above. As a result, it is logical and appropriate to use those 

costs as the basis for estimating overall rule costs.

One common thread in all of these examples, despite differences in numbers of samples, 

locations, etc., is that the absolute minimum dollar amount needed for an entrainment sampling 

exercise is $100K. However, these minimum costs can be considerably higher at some facilities 

due to high organism abundances, sampling access challenges, etc., and costs could easily climb 

to $500K, depending on the sampling scenario (even with number of samples remaining equal).

Further, costs would be expected to be higher for facilities with multiple generating units and/or 

cooling water intake structures. Accordingly, it is clear that these lower estimates are not 

appropriate to consider in a national scale estimate; they may represent the true costs for some 

facilities, but are not likely to be representative of costs on a wider scale.