April 07, 2016
The April 2015 issue of the Iowa Water Environment Association (IAWEA) Reporter
magazine featured an article titled "Mount Pleasant Stays Ahead of the Game" about
major wastewater treatment and collection improvements at the City of Mount Pleasant, Iowa.
MOUNT PLEASANT STAYS AHEAD OF THE GAME
Planning major improvements in wastewater treatment and collection
By Daniel C. Solchenberger, P.E. - Shive-Hattery, and Howard Johnson, P.E. - Shive-Hattery
It seems like every week you can hear or read a news report about how America’s infrastructure is failing. Come to Mount Pleasant, Iowa, and you will hear a different story. This southeastern Iowa community has a long history of keeping their infrastructure up to date with comprehensive planning and timely implementation. Mount Pleasant’s City Administrator Brent Schleisman said, “We have made a concentrated effort since the mid-1990s to upgrade all of our infrastructure. You have to do that once every 50 years.” He added, “We have tackled almost every major thing the City does.”
This attention to infrastructure helps the City attract new businesses and encouraged existing businesses to grow their operations in Mount Pleasant, examples include:
- MM Composite: developer and seller of high quality composite components to the wind energy industry globally.
- NCI subsidiaries Ceco Building Systems and Metal Coasters: designs and manufactures pre-engineered structures used in the construction of commercial, industrial, recreational and community buildings.
- The City purchased Crossroads Industrial Park in 1996 to attract industrial and distribution facilities. Today, there are six new companies in the park that employ close to 750 people.
For a town of about 8,700 people, that is a significant increase to the area’s workforce. The newest project the City has planned is upgrading its wastewater treatment and collection system. Through the implementation of this plan, the City will provide up-to-date facilities, meeting stringent new regulatory requirements, and save their constituents over $2.5 million in the process. The new wastewater treatment and collection system upgrades will continue this well established pro-growth pattern well into the next decade.
Wastewater Facilities Needed an Upgrade
“The City of Mount Pleasant places a high value on growth and providing a favorable climate for growth. The Iowa Department of Natural Resources (DNR) will not permit the City to grow without a major upgrade in the wastewater system,” Schleisman explained. “We built our Sequencing Batch Reactor (SBR) Plant in 2000. It was a $15 million project.” With talk of new rules in 2010 from the DNR, Mount Pleasant did an aggressive Inflow and Infiltration (I&I) study. “We were cleaning, lining and replacing manholes every time we had any work done on the system. We televised a third of the system and replaced two-thirds of the manholes in a three-year process,” Schleisman said.
In 2013 the City received their new NPDES permits, mandating improvements at both the SBR (Main) and the Northeast lagoon WWTPs. The SBR plant treats wastewater using biological processes to reduce organic and ammonia levels so it can be safely discharged. The SBR plant currently treats over 90 percent of the wastewater in our system so it was time to make a decision to continue operating and maintaining two systems, the lagoon and SBR plant, or go to one system.
Deliberative Long-Term Planning Process
The City’s Sanitation Committee, made up of volunteers and elected citizens, handles this type of planning. The committee selected Shive-Hattery and Warner Engineering Associates to collaborate on the project. “We worked closely with both firms,” Schleisman said. . Schleisman also works closely with Larry Hite of Prairie Service, Inc., the contractor that operates the system for the City. Larry’s team manages the facilities 24/7 and also works with the Sanitation Committee. The Facility Plan has been completed and at the conclusion of this process the decision was made to upgrade the SBR Plant and eliminate the lagoon, going to one system. They realized they had a good asset in the SBR plant, so they took advantage of this by investing in it. They are one of the first cities in Iowa that has embraced nutrient removal while also eliminating one of their two treatment plants along with the related unnecessary costs.
Benefits of Going from Two Treatment Plants to One Upgraded Facility
The recommended plan will transition to one upgraded facility. Key benefits associated with the plan include:
- Optimizes the use of the SBR Plant, which is less than 15 years old and in good condition. It has capacity to handle current and projected future flows including existing flows from the Northeast Lagoon. With treatment upgrades to meet new permit limits, the SBR plant will handle all of these needs.
- Eliminates discharge from the Northeast Lagoon to Big Creek which complies with the more stringent water quality requirements that are likely to continue into the future (and possibly even get tighter).
- Provides better use of funding. Instead of spending to upgrade the lagoon, the money can be used to fund collection system improvements and/or help fund improvements that reduce O&M Costs.
- Simplifies the permit process by reducing the number of NPDES permits, O&M, monitoring, and DNR reporting to one facility.
- Overall, the SBR Plant provides superior treatment and greater flexibility compared to lagoon treatment. Investing in the SBR Plant and collection system (in lieu of lagoon upgrades) will better serve the City now and into the future.
- The City also derives some significant financial benefits:
- Saves more than $2.5 million in capital cost.
- Reduces O&M (operations and maintenance) costs significantly
- Reduces risks and NPDES permitting costs. Unifying the operation into one plant cuts permit costs in half.
Scheduling And Financing
The initial plan outlined a timeline through 2026. The timeline breaks down by phases, starting with the SBR permit compliance, with various project designs due by 2017, and construction on going from 2016 through 2023. The Northeast Lagoon portion also has a November 2020 completion date. Sanitary Sewer rehabilitation will continue through late 2026. Including the costs of engineering and planning, the committee currently expects the final costs to total $15 million to $18 million. The team will complete plans for the various projects in each phase with construction starting when funding and IDNR approvals are completed.
The user charge system and associated Sewer Revenue Fund cover the cost of the wastewater system. Individual contributors currently pay a minimum of $7.50 per month plus a user charge of $4.70 per 1,000 gallons. Contributors with wastewater of higher strength than normal also pay a surcharge. The City will be meeting with their financial advisor to develop the approach for financing the improvements. They will look at outside funding sources and also review current cash flow of the existing Sewer Revenue Fund, existing debt, and user charges.
Other Projects in the Works
It’s a philosophy of Mount Pleasant to look down the road and anticipate things. “We don’t want the City to be a hindrance to living and working here,” Schleisman said. Current plans include construction of an additional water well, improvements to roads and sewers, parks, and bike trails. The City also has a goal of changing every street light to an LED fixture over the next three years.
They are also upgrading the police department’s facilities. The recent $900,000 project converted a portion of a vacant supermarket into a modern police headquarters. Including site development and “soft costs” (fixtures, furniture and equipment), the police station was completed for $1.3 million. The project is the first IJOBS project completed in the State of Iowa. The previous police station facility was 4,000 square feet and not energy efficient. The renovated space doubles the square footage to include office space, interrogation rooms, weight room, locker rooms, squad room, and training room. It also provides evidence storage and a garage for police vehicle maintenance. The new facility also includes green design principles, making use of many existing elements. The new roof has a white extremely durable synthetic rubber roofing membrane to reflect rather than absorb the sun’s heat. It also adds four inches of rigid insulation for an increase R-value. Insulated glass on the front also helps provide energy conservation.