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Site Visit Report 

Crawford Generating Station 

3501 South Pulaski Road 

Chicago, IL 60623 

August 4, 2009 

1.0 Background and Objectives 

The Environmental Protection Agency (EPA) is in the process of developing 

316(b) cooling water intake structure requirements that reflect the best technology 

available (BTA) for minimizing adverse environmental impact for all existing 

power plants and manufacturing facilities. As part of this process, EPA staff is 

visiting electric generators and manufacturers to better understand the cooling 

water intake structure (CWIS) technologies in use at facilities, including the sitespecific characteristics of each facility and how these affect the selection and 

performance of CWIS technologies. EPA is also visiting facilities to better 

understand cooling water use and specific issues or technologies that can affect 

316(b) compliance. Crawford Generating Station (Crawford) was selected for a 

site visit due to its urban location. 

2.0 Facility Description 

Crawford is located on a 70 acre site in Chicago and owned by Midwest 

Generation (Midwest). The facility withdraws cooling water from the Chicago 

Sanitary and Ship Canal1

 and began operations in 1923. The facility’s NPDES 

permit (IL0002186) expired on April 30, 2005, but has been administratively 

extended. Crawford employs approximately 110 workers. 

3.0 Electricity Generation and Transmission 

Crawford has 2 coal-fired generating units (Units 7 and 8)2

 with a total generating 

capacity of 581 MW.3

 The facility operates as a baseload generating station,4

 

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 The canal was created to connect Lake Michigan with the Mississippi River system, allowing for 

expanded shipping routes. Facility representatives noted that the canal receives all of the effluent from the 

area’s wastewater treatment plants and other similar effluent discharges; as such, the waterbody has not 

been designated as supporting contact recreation, has less stringent water quality standards than other state 

waters, and generally provides poor habitat. All of Chicago’s urban power plants were also sited on the 

canal, as it provides a constant depth and water flow due to the system of locks and dams. The Army Corps 

of Engineers and Chicago Metropolitan Water Reclamation Department (MWRD) control the water levels 

within the canals; facility representatives noted that water levels can fluctuate by several feet on a daily 

basis. 

2

 Units 1 through 6 are currently retired. Unit 7 began operations in 1958 and Unit 8 in 1961. Units 7 and 

8 use pulverized low sulfur Powder River Basin coal but are also capable of burning natural gas; however, 

fuel costs limit the use of gas to emergency situations. Coal is delivered by barge; the facility can no longer 

receive coal via rail. 

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 Unit 7 and Unit 8 have a generating capacity of 234 MW and 347 MW, respectively. 

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 Crawford’s gross capacity rate for 2009 was 49.4% for Unit 7 and 56.7% for Unit 8. 
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providing both electricity and voltage support to the Chicago area. The facility 

has one scheduled outage per year for each unit; typically one unit is taken down 

in the spring and the other in the fall. Maintenance outages vary from 10-50 days, 

depending on the extent of activities required. 

 

4.0 Cooling Water System and Intake Structure 

Crawford employs a once-through cooling water system (CWS); it operates six 

single-speed circulating pumps (two for Unit 7 and four for Unit 8). The facility 

usually operates all of its pumps when generating, but may cycle off some pumps 

in the winter or during periods when the unit(s) are not operating. The design 

intake flow (DIF) is 593 million gallons per day (mgd) (including service water) 

and facility representatives estimated that the average actual intake flow (AIF) is 

approximately 500 mgd. 

Crawford’s CWIS is on the shoreline at the end of a 400 foot canal off the 

Chicago Sanitary and Ship Canal. It is the original CWIS that began operations in 

1923, but was expanded in 1927 to accommodate the now-retired Units 5 and 6. 

The CWIS consists of a weir wall along the bottom of the canal (to screen debris 

and sediment), an angled trash rack, and 11 coarse mesh (3/8”) vertical traveling 

screens; four are eight feet wide and seven are six feet wide. The screens are 

washed (four per wash cycle) once per shift and debris and fish are deposited in a 

perforated basket for dewatering and eventually disposed of in a landfill.5

 Once 

per year, a diver is used to manually clean debris at the trash racks; this cleaning 

takes approximately 3 weeks. The design through-screen velocity is 2.26 feet per 

second (fps). 

An additional four intake bays are located in the screenhouse, but are not open to 

the source water; these pumps (2 screenwash and 2 fire suppression) withdraw 

from the common sump behind the traveling screens. 

The facility’s NPDES permit does not contain any 316(b) requirements. 

The facility discharges into a second 400 foot long canal just upstream of the 

intake canal. A barge is positioned at the discharge canal to promote thermal 

mixing in the Chicago Sanitary and Ship Canal. 

5.0 Impingement and Entrainment Information 

In 2004-2005, Crawford conducted impingement and entrainment sampling in 

preparation for complying with the 2004 Phase II rule. Weekly impingement 

samples (not impingement mortality) were collected for a 24-hour period. A total 

of 7778 organisms were collected, consisting of 41 species (27 of which are 

native species); eight species comprised 94% of the biomass collected. The 

 

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 Per state law, the facility is prevented from returning anything back to the waterbody. 
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projected total annual impingement at the average actual intake flow was 53,000 

organisms per year and 60,500 organisms at the design intake flow. 

Entrainment samples were collected during the spawning season (May through 

August). Weekly, the facility collected four six-hour samples and pumped them 

through a screen; 2227 organisms were collected, most of which were cypranids 

and clupeids. On an annualized basis (using the actual intake flow), Crawford’s 

annual entrainment was estimated to be 47.3 million eggs and larvae. 

Facility representatives stated that they had not finalized plans on how Crawford 

would have complied with the now-suspended 2004 Phase II rule. 

6.0 Cooling Tower Feasibility 

In 2008, Midwest conducted a feasibility study for converting several of its plants 

to closed-cycle cooling. The study (conducted by Sargent & Lundy) concluded 

that there is sufficient space to install towers at Crawford, but that the cost would 

be approximately $145 million6

 (order of magnitude cost estimate). (See 

Attachments D, E, and F.) Facility representatives stated that financing and other 

considerations would likely render installation of cooling towers at this site 

impractical. 

7.0 Debris Handling 

Crawford screens a very large volume of trash from the canal; approximately 60 

tons of trash is removed each year. Facility representatives noted that Crawford is 

not permitted to return its screen wash water to the canal. Loading from other 

types of debris does not appear to be a major operational concern. 

Facility representatives noted that typically, city workers collect trash by boat 

following storm events; converting to closed-cycle cooling would lead to a 

significant increase in the volume of trash in the Chicago Sanitary and Ship 

Canal. 

Facility representatives noted that, in recent years, the CWIS has experienced 

significant clogging from nylon fibers in the source water; they continue to work 

with local officials to locate the source (suspected to be a large combined sewer 

overflow (CSO) discharge located directly upstream of the station). 

 

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 The study assumed that mechanical draft towers with plume abatement and drift eliminators would be 

installed and that existing structures on the site would need to be relocated. The study did not consider 

permitting or other technical feasibility concerns (e.g., conflicts with existing piping); it was an order-ofmagnitude capital cost estimate only. 
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8.0 Repowering/Future Uses 

Facility representatives stated that there are no plans to expand the facility; they 

also noted that natural gas capacity in the area precludes repowering. 

9.0 Cooling Ponds 

 

There are no cooling ponds at the site. 

10.0 Ownership 

Crawford is owned by Midwest Generation, an investor-owned company and 

subsidiary of Edison International. 

11.0 316(a) 

The facility’s NPDES permit does not contain any 316(a) limits. The Chicago 

Sanitary and Ship Canal is a man-made waterway designed to convey POTW 

effluent and is manipulated to achieve flood control for the City of Chicago, as 

well as accommodate heavy commercial barge traffic. As such, it has less 

stringent water quality standards for most pollutants, including temperature. 

Crawford has been consistently able to comply with the existing thermal limits 

such that no 316(a) variance has been required. 

12.0 Ash Handling 

Fly ash is sent to an offsite landfill, due to the use of activated carbon injection 

(ACI) for mercury control on both units. The ACI systems have been in service 

since July 1, 2008; prior to the start-up of these units, fly ash was sold for 

beneficial reuse. 

 

13.0 Air Emissions Controls 

Crawford uses electrostatic precipitators for particulate control, overfired air for 

NOx reduction, and activated carbon to remove mercury. 

14.0 Additional Information 

Facility representatives also presented information on debris collection at the 

Joliet Station, located further downstream on the Lower Des Plaines River; that 

facility collects 30 tons of trash per year. 

Facility representatives stated that many facilities owned by Midwest employ 

once-through cooling. Facility representatives stated that they had conducted 

impingement and cooling tower feasibility studies at several of Midwest’s nearby 

facilities, including Joliet, Will County, and Fisk. The estimates were as follows: 
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Joliet (Unit 6) $88 million to $109 million, Joliet (Units 7&8) $232 million to 

$296 million, and Will County $187 million to $233 million. Facility 

representatives provided detailed information on Fisk Generating Station and 

EPA has prepared a separate report outlining that information. 

There has not been any determination made at this time for any of Midwest 

Generation’s 316(b)-affected facilities as to whether closed-cycle cooling systems 

are technically feasible, as the order-of-magnitude cost estimates did not consider 

permitting or other technical feasibility concerns (e.g., conflicts with existing 

piping, infrastructure, overhead power lines, proximity to airports, major 

highways, residential areas, etc.); it was an order-of-magnitude cost estimate only. 

The facility installed a heat treatment system for zebra mussel controls; an 

adjustable gate was added to the discharge point and a concrete pipe was installed 

to allow heated effluent to be recirculated to the intake canal. To date, the facility 

has not used the system. 

The facility has positioned a river barge across the intake canal in an attempt to 

exclude floating debris and prevent recirculation of heated effluent. 

Facility representatives stated that the city has a significant problem with CSOs. 

Approximately 30-60 CSOs occur each year from over 300 separate discharges 

throughout the Chicago Area Waterway, sending untreated sewage into the canal; 

this often depletes the entire supply of dissolved oxygen from the waterbody, 

further degrading the long-term habitat quality. 

Facility representatives expressed disappointment that restoration is no longer a 

compliance alternative; Midwest has previously participated in restoration 

projects and would prefer to take that approach again. Facility representatives 

noted that state resource agencies are often very supportive of restoration projects. 

As an example, Midwest has worked with the Illinois Department of Natural 

Resources (DNR) at one of their cooling ponds at a now-closed power plant in 

Illinois to develop a healthy and popular recreational fishery. Facility 

representatives also noted that installing closed-cycle cooling, especially at 

facilities located on a man-made, artificially controlled waterways such as the 

Chicago Sanitary and Ship Canal, could prove to be a lost opportunity to further 

protect or restore existing fisheries in other less urbanized/impacted waterways 

and help state agencies in maintaining their resources; instead, closed-cycle 

cooling may actually benefit invasive species, by reducing the culling of those 

species via impingement and entrainment. 

Invasive species have come to the forefront of public attention in the months 

following the site visit, beginning with Rotenone treatment of 6 miles of the 

Chicago Sanitary and Ship Canal in early December 2009 in order to attempt to 

eradicate Asian Carp from the waterway before they enter Lake Michigan. The 

State of Michigan has sued the State of Illinois, the US Army Corps of Engineers, 
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and the Metropolitan Water Reclamation District of Greater Chicago (who 

controls the ship canal), demanding that all pathways to Lake Michigan be 

closed—an action that would significantly impact all Chicago Sanitary and Ship 

Canal users. A comprehensive Asian Carp Control Strategy has been developed 

by the US Army Corps of Engineers, USEPA, USFWS, IDNR, and other Federal 

and State natural resource agencies, largely targeting the Chicago Sanitary and 

Ship Canal as the last line of defense against Asian Carp invasion of the Great 

Lakes. As such, they are looking to implement a series of additional barriers, 

deterrents, and eradication efforts on this waterway—all of which will impact the 

existing indigenous aquatic community more than any power plant’s impingement 

or entrainment effects. 

Consideration of additional impingement and entrainment controls on this 

waterway, in light of recent and continuing Asian Carp defense planning seems 

counter to these efforts, which have state, federal and international support. 

Attachments 

Attachment A List of Attendees 

Attachment B Aerial Photos 

Attachment C PowerPoint Presentation (August 4, 2009) 

Attachment D Engineering Diagrams for Cooling Tower Locations at Crawford 

Attachment E Summary of costs from Sargent & Lundy cooling tower feasibility 

study 

Attachment F Executive Summary of Final Draft Impingement Mortality and 

Entrainment Characterization Study, Crawford Station December 

2007 

 
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Attachment A--List of Attendees 

Paul Shriner, EPA 

Jan Matuszko, EPA 

Sean Ramach, EPA Region V 

John Sunda, SAIC 

Kelly Meadows, Tetra Tech 

Julia Wozniak, Midwest Generation 

Bill Constantelos, Midwest Generation 

Luke Ford, Midwest Generation 

Dan Dammer, Midwest Generation 

Brenda Brock, Midwest Generation 
Copyrighted page/s removed. Copyrighted 

material is not available in Regulations.gov since 

it may not be reproduced without consent of the 

copyright holder. 

Please contact the EPA Docket Center, Public 

Reading Room to view this document. 

Address: 1301 Constitution Ave, NW 

Room 3334 

Washington, DC 20004 

Telephone: 202-566-1744 

Fax: 202-566-9744 

Email: docket-customerservice@epa.gov
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Attachment C—PowerPoint Presentation (August 4, 2009)

Please see the attached materials. 

Attachment D—Engineering Diagrams for Cooling Tower Locations at Crawford 

Please see the attached materials. 

Attachment E—Summary of costs from Sargent & Lundy cooling tower feasibility 

study 

Table ES-1 (from draft Sargent and Lundy April 2008 report) 

Cost Summary of All Wet/Dry, Wet/Dry Convertible, and Wet Non-Convertible 

Towers, and Wet/Dry O&M Costs 

Unit Station 

Total 

Gross 

MW 

Capital Cost 

Wet/Dry 

Towers ($) 

Capital 

Cost Wet 

Convertible 

to Wet/Dry 

($) 

Capital 

Cost 

Wet 

Only ($) 

Annual 

O&M 

Cost – 

Wet/Dry 

($) 

Wet/Dry 

Capital 

cost ($) 

per kW 

Fisk 19 348 $119,952,645 n/a* n/a* $1,926,728 $345 

Crawford 

7&8 

585 $144,652,125 n/a* n/a* $3,579,632 $247 

*Note that wet only towers would not be able to be permitted at these facilities, due to 

their close proximity to residential areas and major highways/roads/airports. 

Attachment F—Executive Summary of Final Draft Impingement Mortality and 

Entrainment Characterization Study, Crawford Station December 2007 

Please see the attached materials.