Wet Weather Issues

During heavy rains, storm water enters and overloads the wastewater collection system which can cause overflows of very dilute untreated wastewater to the river and other areas. In 2003, St. Marys entered into a Findings and Orders (F&O) agreement with Ohio EPA to address the flow capacity of our collection system and treatment plant, especially during wet weather periods. The agreement requires the City to study, plan, finance, and complete improvements necessary to remove wet-weather sanitary sewer overflow by 2013.

SSO Response Plan

One component of our agreement with Ohio EPA is a requirement that the City develop and implement a Sanitary Sewer Overflow (SSO) Response Plan. The plan, developed by modifying existing practice, specifies activities we must take to protect human health and the environment during wet weather when overflows can occur. The City's plan was submitted to Ohio EPA in March 2004, and officially endorsed in June 2004.


Another component of our agreement with Ohio EPA is a requirement that the City implement a "Capacity, Management, Operation, and Maintenance" (CMOM) program, where strategies are developed for the effective operation and maintenance of the wastewater collection system and the wastewater treatment plant. Again, the majority of the requirements in a CMOM were already being done by the City. The City's plan was submitted to Ohio EPA in September 2004, and accepted by the Agency on August 11, 2005.


The third component of our agreement with Ohio EPA is a requirement that the City implement a "System Evaluation and Capacity Assurance Plan" (SECAP) wherein the flow capacities of all our wastewater facilities are evaluated, recommendations for improvements to address deficiencies are made, and a schedule developed for construction. This plan was submitted to Ohio EPA on March 7, 2006, and accepted by the Agency on March 28, 2006.

Improvement Planning

The required improvements are very important to the future of St. Marys, coming with a high price tag and taking place over a period of years. St. Marys City Council, therefore, authorized the execution of a general services agreement with Arcadis, a professional engineering firm based in Toledo. The firm will guide the City as we progress through studies, planning, and construction for the required improvements. The following activities have been completed:

  • A sewer rate study determined that sewer rates must be increased to pay for the costly improvements. St. Marys City Council authorized a 65% increase in sewer rates, spread over three years, at their March 13, 2006 meeting. The rate increase was effective April 1, 2006.
  • A wastewater treatment plant facilities plan was completed in October 2005. The plan guided St. Marys through the construction of a new wastewater treatment plant.
  • The SECAP completed in 2006 identified several wastewater-related deficiencies that need to be addressed to meet the F&O agreement. The construction of a new treatment plant was the first and most significant project. The remaining issues include pump station and collection system capacities and satellite collection systems.
  • For the past several years, St. Marys has contracted a sewer repair project each year to address pipe deterioration, excess storm water entering the collection system, and other reasons. Projects are determined based on investigative work.
  • Completed in 2008, the Northeast Relief Sewer Project diverted all flows in the northeast portion of St. Marys to the Northeast pump station. A mechanical and electrical upgrade of the station was included. The project, paid in part by a State of Ohio Issue I Grant, provided additional capacity at the New York Central pump station, part of a larger plan to address storm water flows.
  • Construction of a new wastewater treatment plant began in January 2008; it began treating flows in May 2009, and construction was considered complete in November 2009. The total contracted cost was $11,012,020, financed through the Ohio EPA Water Pollution Control Loan Fund (WPCLF). St. Marys cannot rest just because the new treatment plant is in operation. There remains a lot of work to do on the collection system, work that will be expensive.
  • The Southwest Pump Station project was completed in 2012. The project included the construction of a second pump station near West School that handles all flows from Auglaize County-owned sewer systems around Grand Lake St. Marys, pumping them directly to the wastewater treatment plant through approximately 7,000 feet of new 14-inch force main. The existing pump station near West School was converted to handle only those flows from within City limits, re-establishing the original design capacity and significantly reducing the demands placed upon the station during wet weather. A very unique feature of the project is that both pump stations are able to serve as a back-up to the other. The project will result in a significant decrease in sanitary sewer surcharging, overflows, and basement flooding in the southwest area of the City. Total project cost was $1,536,989 ($1,065,470 for pump station, $471,519 for force main).

Why Storm Water is Such a Problem

An 8 inch sewer line can service the sanitary needs of as many as 456 homes. Yet, during times of significant rainfall, that same 8 inches sewer line can be overloaded by only 36 homes if storm water can enter the line through improper or unauthorized connections such as inflow (direct connections, home sump pump systems, etc.), or infiltration (small voids in sewer lines, home laterals, and manholes). Excess storm water causes two serious problems when it finds a way to enter sewer lines:

One obvious problem is sewer backups which can occur when a sewer system is required to handle more than its designed flow. These backups can cause serious problems for the affected homeowner and severely restrict future residential and commercial development.

Another result is that all flows that enter sewer lines must be pumped and treated at the Wastewater Treatment Plant. Handling and treating water that isn't sanitary in nature before it enters the sanitary system increases the costs to all users significantly.

We Need Your Help

St. Marys is committed to removing improper connections. Here's where we need your help. Many residents may not know if they have an improper or unauthorized storm water connection to the sanitary sewer system. By doing a visual inspection of your residence to determine if you have an unauthorized connection, you can prevent storm water from your property from entering the sanitary system. For help in this inspection, please refer to the Unauthorized Sewer Connection Awareness Program (PDF).