Trotter and Associates, Inc. has become highly respected for successfully planning, designing and implementing a wide range of water and wastewater infrastructure solutions. The potable water system is one of the most important services a community can provide as it protects public health, enhances quality of life, is instrumental in fire protection, and supports economic growth within the community. As such, systems must be designed and operated such that interruption of service is an unusual event.

As communities with aging infrastructure continue to grow, there is a need to address the quality, quantity, and efficiency of delivering potable water. Driven by the Safe Drinking Water Act (SDWA) Amendments, water systems are being affected by a new emphasis on microbiological safety, disinfection requirements, reduction of disinfection by-products (DBPs), new maximum contaminant levels (MCLs) for arsenic, organic contaminants and radionuclides and minimization of lead and copper concentrations “at the tap.” Communities must find new supply sources, better and more efficient treatment technologies, and the methods to cost effectively maintain and expand existing distribution systems.

Part of a public official’s charge is to invest their community’s limited resources wisely. That serious responsibility includes decisions regarding improvements to the community’s water system. TAI excels in the planning, design and implementation of water system improvements. Our team of professionals works closely with our clients, enabling staff and elected officials to make informed decisions concerning the improvements to be implemented. TAI’s team will find the strengths of the existing infrastructure and maximize those strengths in development of a solution that fits the community’s current and long term needs.


TAI provides its clients with a comprehensive suite of water system engineering services including:

  • Water system master planning and modeling
  • Water distribution design
  • Water supply and storage design
  • Water treatment engineering

Water Master Plans & Modeling

Trotter and Associates, Inc. has developed Water System Master Plans for several communities in Northern, IL. TAI’s formula for success includes a comprehensive review of the existing infrastructure, working closely with the operational staff, development of specific solutions, and preparation of concise reports. Ultimately, TAI provides a product that demonstrates the system’s strength, weaknesses, needs and solutions to elected officials and the public.

As part of the Master Planning process, TAI is often requested to provide distribution system modeling. TAI’s professionals currently utilize WaterCad V8i which is the latest version of the Bentley modeling software. In addition, TAI often maintains, updates and provides ongoing analysis for communities to address the potential impacts of infrastructure improvements or pending development.

Water Distribution

The TAI staff has completed numerous water distribution system modeling and design projects. Both new distribution systems and older, dual pressure zoned systems have been modeled with WaterCAD® software. Distribution system models have proven to be valuable tools for determining the performance of the distribution system under normal conditions, as well as during emergency situations or stressed conditions. The WaterCAD® software allows for distribution system characteristics to be modeled for several unique scenarios, some of which include:

  • Fire Flow Protection
  • Watermain Breaks
  • Wells and Towers Out of Service
  • System Dynamics During a Contamination Event
  • Computing Water Age
  • Analyzing Constituent Concentrations
  • Performing a Trace Analysis

Water Supply

The TAI staff is experienced in water supply projects. Through close working relationships with local drilling companies and State agencies, TAI is able to readily identify potential sources for water. The use of historic data enables TAI to predict both water quality and quantity from each source. The TAI staff can assist an owner in identifying, designing and constructing a viable public water supply system which will meet state standards. As part of the preliminary investigation, the staff reviews water quality and treatment requirements. Once the treatment requirements have been identified, the total cost can be estimated including the operation and maintenance requirements associated with each source. Operation and maintenance costs are commonly more significant in the evaluation than the original construction cost. A comprehensive cost analysis ensures that the client is able to make informed decisions.

Water Storage

TAI’s staff has assisted many communities with evaluating, designing, and constructing water storage improvements including ground storage reservoirs, booster stations and elevated storage tanks. The master plan and distribution system model provide the basis for decisions on sizing of storage facilities. The master plan will define the maximum hourly usage which is utilized in formulating the balance between water system supply and storage. The distribution system model will identify the hydraulic grade line to be maintained. From this information, storage volume and configuration can be established. Ground storage reservoirs are typically located at well or treatment sites. One of the major advantages of ground storage reservoirs is the flexibility they provide operators to maximize cycle time for well pumps or treatment units. For example, an operator can elect to run the wells and treatment facilities at night when electrical demand charges are lowest and meet the systems demand during the day with the booster pumps only.

Elevated storage size and location are dependent on the characteristics of the distribution system as well. Once the storage volume and site are selected, the style and configuration of the tower must be determined. The options include the older style multiple leg tanks, spheroids, standpipes and pillars. Each alternative generally has a volume range in which it is economical to construct. Therefore, the style of elevated storage tank may be determined by a combination of factors including storage needs, aesthetics and site constraints.

Water Treatment

TAI’s professional staff participates in postgraduate studies, technical seminars and continuing education programs to acquire the latest and most advanced information in the rapidly changing field of water treatment. This ongoing training enables staff to make recommendations based on the most current technology — a clear advantage to our clients. TAI recognizes the importance of incorporating provisions into the design for modifications to accommodate pending regulations or expansion in the future.

TAI’s water treatment experience includes barium, radium, radon, iron and manganese removal, as well as removal of organic and inorganic compounds. Our staff works closely with manufacturers to fully understand the requirements of each piece of equipment. By incorporating the manufacturer into the design team, each entity understands the project’s objectives and constraints. TAI’s process engineers have extensive experience in the design of a variety of water treatment processes including: chemical pre-treatment and post treatment, gravity and pressure filtration, membrane systems, HMO filtration systems as well as Ion Exchange systems.

In summary, TAI’s process and municipal engineers have the expertise to effectively implement any water treatment process along with integrating booster stations, storage facilities and distribution system improvements in order to deliver safe drinking water to everyone’s tap.