Our work

Boone, IA

Boone Welcome Train

Project: Boone Welcome Train Boone Rotary Club – Welcome Train Location: NE Corner of Hwy 30 and Story Street, Boone, IA Ownership:  Iowa Department of Transportation owns the land, the City of Boone will be the owner of the train after project completion Boone Rotary Contacts: Dave Cook, Steve Dakin, and Lisa Mount FOX Scope […]

Ames, IA

Courtyard by Marriott

Hotel: Courtyard by Marriott, 120-rooms, restaurant (The Bistro), indoor pool, fitness, and meeting rooms.  $6.2 million facility Address: 311 S. 17th Street, Ames, IA Site: 3.8 Acres Project Highlight: Beneath the parking lot is an underground storm sewer system. FOX was able to satisfy the Ames Code requirements for storm water storage and quality with […]

North Liberty, IA

East Growth Area Utilities – Water and Sewer

A 2011 Sanitary Sewer Service Study done by FOX clearly revealed a critical need to provide sewer service to a future growth area east of the city. Proactive collection system planning made it possible to proceed with almost $5 million in improvements to sewer and water systems, paving the way for additional economic growth. In […]

North Liberty, IA

Water Treatment Plant

Challenge: North Liberty’s Water Treatment Plant was originally constructed in the late 1970s and underwent its first expansion in 2001, a project that was expected to have a 10-year life. However, population growth exceeded optimistic projections and demand was quickly reaching capacity. Upgrades were made to increase well capacity and an Aquifer Storage and Recovery […]

Washington, IA

Water Treatment Plant Improvements

CHALLENGE: The city’s existing water treatment facility, which underwent its last major expansion in 1992, utilized an electrodialysis reversal (EDR) treatment process.  Portions of the facility that housed the city’s high service pump dated back to 1924. While the EDR systems provided the city with many years of reliable service, aging equipment and lack of […]

Marshalltown, Iowa

Water Treatment Plant

Challenge:  A founding partner of FOX Engineering, Dave Fox was responsible for the 1977 design and construction of the original 10 million-gallon-day (MGD) water treatment plant in Marshalltown. In 1997 water demands were increasing rapidly; production at the lime softening plant was approaching capacity, and many components needed to be replaced or upgraded. Major improvements […]

Ames, Iowa

Water Treatment Plant

Challenge: The city of Ames began municipal water service to its residents in 1891; the first treatment efforts followed in 1924. Treatment processes evolved from simple iron removal to more sophisticated lime softening and disinfection, always with a focus on providing the best quality water possible to its customers. The most recent plant expansion occurred […]

Ames, Iowa

Water Treatment Plant – Utilities

Over the past few decades, Ames Water and Pollution Control has chosen FOX Engineering as design engineer for various well and water system improvements. Design for the new 15 MGD water treatment plant, along with site planning, stormwater management, and utility installation, are the most recent improvements. The plant was completed in August 2017. On […]

Ames, Iowa

Water Treatment Plant – Site Development and Stormwater Management

Challenge: FOX began the planning phase for the Ames Water Treatment Plant (WTP) in 2008. An analysis of the city’s facilities showed that a new, larger facility was needed to meet future water demands. For the new site, Ames selected a 43-acre property that would make use of existing infrastructure. Improvements were made to approximately […]

Marshalltown, Iowa

Turner Street Sanitary Sewer Pump Station and Force Main

Challenges: In 2008, the Iowa Department of Natural Resources issued a consent order to the city of Marshalltown requiring elimination of sanitary sewer overflows and basement backups. In response, the city initiated a program to reduce infiltration/inflow (I&I) in the sanitary sewer system and provide collection system improvements for conveyance of up to a 10-year […]

Story County, IA

Hickory Grove Lake Watershed Improvements – Phase 1

Challenge: Hickory Grove Lake is a popular destination for recreation in central Iowa. The 400-acre park and 98-acre lake have campground amenities, a beach for swimming, and fishing opportunities. In February of 2014, FOX Engineering Associates, Inc. (FOX) worked with Story County Conservation (SCC) staff to develop grant applications to the Iowa Department of Agriculture […]

Story, City, IA

South Story City Drainage Improvements

Challenge: Story City initiated a study of its stormwater facilities after major flooding, most recently in 2008 and 2010. On the southern side of the city, flooding caused significant damage to residential properties and jeopardized operations at a Bethany Life assisted living and nursing care facility, home to 200 elderly residents. A study determined that […]

Marshalltown, IA

Biogas Generator Replacement 2016

One of the city’s two biogas engine-generators permanently failed. It was 40 years old and would require more money to fix than it was worth ($1/4M). Sizing a new engine-generator had very little to do with the parameters of the existing engine-generator. The Performance Edge Project reduced the city’s need for capacity.

Grimes, Iowa

North Walnut Creek Grimes Watershed Study

Challenge To provide sound stormwater management practices within the North Walnut Creek Watershed and meet growing development needs, the city needed an evaluation of the watershed to study past development as well as consider future stormwater management needs. This included review of existing land development, urban land management, rural land management, a hydrologic and hydraulic […]

Ames, Iowa

Dotson Drive Extension

Challenge The Ames Community School District facilities at Dotson Drive and Mortenson Road did not have a roadway connection across College Creek to the north.  An extension across the creek was needed to reduce traffic problems and to allow access to the school’s facilities on the north side of College Creek. The proposed roadway extension […]

Grimes, Iowa

FEMA Preliminary Flood Mapping Appeal

Challenge The city of Grimes is one of the fastest growing communities in the state of Iowa. The Federal Emergency Management Agency (FEMA) issued new National Flood Insurance Program (NFIP) preliminary flood insurance rate maps.  The preliminary mapping provided more detailed analysis of the floodplain in and around the city of Grimes and replaced the […]


Conversion to River Discharge

An amino acids plant producing animal feed supplements desired to convert from a pretreatment facility to a direct discharger. The pretreatment plant was a plug flow activated sludge plant consisting of equalization, a three-zone aeration basin, a post aeration anoxic zone, a re-aeration basin, and a final clarifier prior to discharging to a neighboring wastewater treatment plant.


Dissolved Air Flotation Improvements

This pork slaughterhouse facility had a 35-foot diameter dissolved air flotation thickener and an 11’ x 52’ rectangular DAF unit for wastewater pretreatment. FOX was hired to review the DAF performance and recommend improvements.


Flow EQ, Pump Station, and Odor Control

This large Minnesota city owns and operates an industrial wastewater treatment facility which treats wastewater from a hog processing plant. The industrial wastewater facilities consist of flow equalization and an anaerobic contact treatment process which was originally constructed in the late 1950s.

Washington, IA

New Sequencing Batch Reactor Plant

The city (pop. 7326) has treated wastewater at this site since 1924. Facilities included preliminary treatment, primary clarification, single-stage trickling filter, final clarification, and anaerobic digestion. Frequent violations associated with sanitary overflows during storm events mandated action to gain control of the collection system and treatment facilities.

Red Oak, IA

Wastewater Treatment Improvements

The city had operated a trickling filter wastewater treatment plant since the early 1960s. The plant was expanded and rehabbed in the late 1980s. Since that time, the facility reliably met its effluent limits and provided Red Oak with more than 20 years of operation with relatively few improvements.

North Liberty, IA

Membrane Bioreactor Wastewater Treatment Plant: Phase I

Growth brings challenges along with opportunities for innovation and sound environmental choices. North Liberty is a rapidly growing community in Johnson County, near Iowa City. This growth required expansion of the existing wastewater treatment facility, originally constructed in 1998.

North Liberty, IA

Membrane Bioreactor Wastewater Treatment Plant: Phase II

Continued rapid growth (100% since 2007) required implementation of the Phase II plant expansion. FOX completed design and bidding of the expansion in 2015. This project, currently under construction, is truly a team effort with plant staff having a great deal of input on design; it will increase the treatment capacity to accommodate a population of approximately 28,000.

Marshalltown, IA

Energy Efficiency

Performance Edge is the name given to a cooperative effort between the city and Alliant Energy. In 2011, FOX Engineering began a detailed evaluation of the Marshalltown wastewater treatment plant in cooperation with Alliant Energy. The mission was to identify improvements that could be made to the facility that would reduce the plant’s energy consumption with a payback of five to seven years.

Marshalltown, IA

Peak Holding and Pumping Improvements

The existing flow equalization basin and pumping system were inadequate to handle peak flows during major storm events.

Atlantic, IA

Sequencing Batch Reactor Wastewater Treatment Plant

The city (pop. 7,112) has been treating wastewater at this site since 1940. Existing facilities included preliminary treatment, primary clarification, a carbonaceous trickling filter, intermediate clarification, a nitrification trickling filter, final clarification, anaerobic digestion, and liquid sludge storage.

Marshalltown, IA

Municipal Treatment of Industrial Wastewater

In 1988, Marshalltown Water Pollution Control Plant was faced with a problem of increased ammonia loads in the wastewater discharge from a large industrial contributor and more restrictive ammonia discharge limits from IDNR to protect the Iowa River.

Marshalltown, IA

Biosolids Improvements

Since 1939 Marshalltown has treated its wastewater at the same location; as part of the treatment process, inorganic and organic material commonly known as sludge is removed from the raw wastewater. It is treated and eventually land-applied as fertilizer on field crops. After sludge is treated, it is commonly referred to as biosolids.

Manchester, IA

Wastewater Treatment Improvements

The city’s wastewater treatment plant was constructed in the 1950s and has undergone several modifications throughout its 50+ years. With aging facilities that were organically overloaded, plant operators were having difficulty consistently meeting NPDES permit limits.

Grimes, IA

Treatment Plant Improvements

A rapidly growing suburb of Des Moines, (population 8,246) the aging wastewater treatment plant was being severely overloaded by 1997 when FOX began working on the city’s wastewater facility plan (we were also simultaneously working on a facility plan for the water system). With such growth, the facility plan recommended that the treatment plant be upgraded in three phases over the next 20 years.

Council Bluffs, IA

Trickling Filter

In 2009, the city of Council Bluffs WPCP staff requested a plan to upgrade the trickling filter recirculation pump station and replace the motor control center. This project was initiated by FOX to obtain additional grant funds for Green energy efficiency.

Council Bluffs, IA

Wastewater Digester Improvements

The anaerobic digesters were built with the original plant in the 1970s. In 2009, FOX evaluated and designed improvements and repairs to the entire digester complex, including structural repairs to the primary and secondary digester covers, replacement of the sludge heating and gas safety equipment, and upgrade of the electrical and control equipment.

Council Bluffs, IA

Wastewater Treatment Disinfection

FOX teamed with the city on a project resulting in the largest UV installation in the state of Iowa (2011). The disinfection study phase included evaluation of various options for implementation; FOX worked extensively with plant staff to evaluate options specifically suited for the Council Bluffs facility.

Council Bluffs, IA

Screening and Grit Removal Improvements

The water pollution control plant has been operating at its current location since the mid 1970s. The challenge was to retrofit the aerated grit basins that had deteriorated due to age with a grit removal technology to remove finer “sugar sand” grit particles and keep grit particles out of downstream clarifiers and digesters.

Marshalltown, IA

Influent Pump Station and Grit Removal (28 MGD)

The Influent Pumping Station and Pretreatment Building at the WPCP were constructed in 1987 to transport wastewater flows to the treatment plant and excess flow to the holding lagoon.

Council Bluffs, IA

Integrated Fixed-Film Activated Sludge

The city’s wastewater treatment plant experiences significant industrial loads. This plant was originally constructed as a two-stage trickling filter plant.

Charles City, IA

Treatment Plant Improvements

FOX Engineering Associates was retained by the city to assist in solving wastewater permit compliance problems.

Austin, MN

Wastewater Treatment Improvements

The city owns and operates a wastewater treatment facility for its domestic, commercial, and industrial customers.

Marshalltown, IA

Water Tower

The Marshalltown Water Works owns and operates the water distribution system serving Marshalltown and a large portion of the Central Iowa Water Association (CIWA).

Marshalltown, IA

2000 Water Treatment Plant Improvements

Aging facilities and insufficient capacity required the Water Works board to consider how they could best solve these critical issues.

Grimes, IA

Water Treatment Plant

Population growth had stressed the capacity of the water system. There was only one reliable well and it could not meet demand on a peak use day and water quality from the Jordan aquifer well was not good.

Twelve Mile Island; Creston, IA

Ultrafiltration Water Treatment Plant

The $12 million construction project included improvements to every part of the treatment plant, including pumping, chemical feed systems, clarification, and filtration.


Surface Water Treatment Plant

Faced with deteriorating water plant structures and equipment, mounting repair costs, and the ever-increasing difficulty in complying with drinking water regulations, the city realized that critical action was necessary.

Washington, IA

West Side Sanitary Sewer

Collection system planning is a cost-effective way to assess and maintain a city’s current system, and aids in positioning the city for economic growth.

Oelwein, IA

Collection System

Economic development is an essential focus for Iowa communities. In Oelwein, population 6,415, city officials took a practical, pro-active approach to readying themselves for potential activity and growth.

Oelwein, IA

Water Distribution Pressure Zone Improvements

Oelwein was founded in a low lying area and expanded to higher ground as the population grew.

Marshalltown, IA

Iowa River Sanitary Sewer Interceptor

In 2008, the Iowa Department of Natural Resources issued a consent order to the city of Marshalltown requiring elimination of sanitary sewer overflows and basement backups for at least the 5-year storm event.

Iowa Falls, IA

Ellis Avenue Improvements

Since 2000, the city of Iowa Falls has been examining its infrastructure needs. Like many other communities, the city has known economic challenges and slowed growth.

Grimes, IA

Main Street

For over a decade, Grimes Council and staff have planned and strategized for the revitalization of their downtown.

Grimes, IA

Highway 44

A city’s ability to safely and expeditiously move its citizens from one place to another is dependent on a number of services not the least of which is a well-maintained and thoughtfully planned transportation system.

Ankeny, IA

Sanitary Sewer Trunk System

This rapidly growing community located in the heart of the Des Moines metro area needed to plan for future development while remaining vigilant about the existing needs of their infrastructure.

Marshalltown, IA

Water Wells

Frequency of flood events necessitated the revision of the 100-year flood designation of the Iowa River and several wells were threatened. Location of safe, reliable water sources was essential.