CSO Program (1988 to 1997)

MSD officials actively participated with USEPA in the formulation of the initial regulatory requirements for CSOs. In 1988, MSD began an engineering survey of 670 miles of combined sewers, detailing locations and functions of 121 overflows. By 1990 MSD had completed an initial inspection of most of the major combined sewers and an inventory of the major structures and overflow points. This work resulted in the CSO numbering system still in use and a listing of the CSO points in the Morris Forman KPDES discharge permit.

Also during this period of 1990 to 1991, MSD began discussions to establish a separate management program, specifically to review the performance of its combined sewer system in light of the pending National CSO Policy requirements, as well to improve the system’s operating performance, O & M costs, and potential needs for future growth and expansion. In 1991, MSD formalized its CSO program efforts and retained outside engineering consultant services to assist with program implementation. During the first year of the consultant contract, the primary emphasis was on an update of the CSO Inventory, site inspections of each overflow point, a water quality sampling program, a flow monitoring program at fifty points within the combined system and development of a hydraulic model of the combined system. All of this work was completed by early 1993.

One of the first major undertakings of the CSO program was preparation of a detailed, comprehensive inventory of MSD’s combined sewer system infrastructure. Field visits were made to inspect, document and update the physical conditions of the various regulators, diversion structures, sanitary and flood pumping facilities. Written descriptions were prepared of each structure to provide a ready resource to better describe the intended function of each structure and how its performance was related to adjacent system components. This CSO Inventory became the reference book for the CSO system.

A second major undertaking of the CSO program was the development of a mathematical model of the combined sewer system. MSD reasoned that a well-constructed, calibrated sewer system model would provide a valuable tool that could be used to analyze system performance under a variety of conditions, including assessing CSO control alternative technologies. A two-year effort was undertaken to construct and calibrate the model. During this period, over 50 flow monitoring stations were installed throughout the system to gather actual flow measurements under a variety of dry weather and wet weather conditions. This database provided the basis for calibrating the model, in addition to providing a better understanding of the system response to wet weather events.

MSD, in cooperation with the United States Geological Survey (USGS), initiated a stream monitoring, rain gauge and streamflow data collection program in 1988. This program was a long-term effort to provide baseline water quality data on Jefferson County streams and to track water quality trends as more areas were sewered and package wastewater treatment plants removed. The stream monitoring (quality and flow) consisted of bi-weekly sampling at 27 locations. Ultimately, this data was used to develop correlations between CSO discharges and water quality. Only two of these sites were within the CSO area, one on the South Fork of Beargrass Creek and one on the Middle Fork of Beargrass Creek. Analysis of the data from these sites yielded inconclusive results. Therefore, in 1992 with the financial assistance of an EPA grant, MSD initiated a stream and CSO sampling program to determine the effects of CSOs on water quality. This program consisted of both automatic samplers on the overflow structures and grab samples of the creek upstream and downstream of strategic overflow locations. Recommendations from this project were to develop and implement a long-term stream/CSO monitoring program, including bi-weekly streamflow monitoring on strategic reaches of the forks of Beargrass Creek and quarterly CSO sampling at twelve locations. This monitoring effort continues today.

Many portions of the combined sewer system area have a long history of surface flooding and basement backups. In 1992, twelve areas plagued by basement backups and surface flooding within the combined system were identified and added to the scope of the CSO program. This resulted in the initiation of a major effort toward private property protection through the basement backflow preventor program, now the Plumbing Modification Program and the eventual construction of three flood/CSO control basins within the combined system (Wheeler, Brady and Executive Inn).

In November 1993, per the requirements of the Morris Forman KPDES permit, the first Combined Sewer Operation Plan (CSOP) was presented to the Kentucky DOW. The CSOP was the initial effort to document in one place the various activities that were taking place under the CSO program and to document the estimated pollutant loads from the combined sewer system and the success of the efforts to reduce the pollutant loads. This first report provided a complete update of MSD’s CSO control efforts since 1991. The CSOP was resubmitted each year until the advent of the WATERS report in 1999, which now contains CSOP annual update information.

In April 1994, the National CSO Control Policy was issued by USEPA, which described the fundamental approach to developing a CSO control program. MSD reviewed in detail the two philosophical approaches described in the Policy, Presumptive or Demonstrative, to determine the direction that its CSO program should follow. MSD complied with the CSO Policy by submitting the required components which included the Region 1 Long Term Control Plan (LTCP) draft submittal with the 1996 CSOP, the Regions 2 & 3 LTCP draft submittal with the 1997 CSOP, and the Nine Minimum Controls compliance report submittal also in 1997. Alternative evaluations with regards to sensitive features and cost benefit analyses were performed in conjunction with LTCP development.

Throughout the initial years of the CSO program, the CSO team worked closely with the Industrial Waste Department in an effort to quantify the effects of industrial discharges on combined sewer overflows. An inventory of the industrial discharges tributary to each CSO was developed. The sampling program also attempted to develop information relative to pollutant loads in industrialized areas. The initial CSO Program efforts included an inventory of all SIUs within the MFWTP service area (this service area contains all of the combined sewer system as well as large areas of separate sewers). The SIU inventory included a tabulation of 123 SIUs, their average daily flows, average pollutant concentrations and loads, receiving sewer and downstream CSOs. Additionally, MSD had a Strategic Manhole Program (SMP) to provide a method to detect potential problems within the sewer system. The MFWTP service area was divided into 28 areas based on drainage basins and sewer service areas with strategic manholes located in each identified area. The strategic manholes were selected based upon safety, area industries, drainage patterns and adequate fixtures to allow automatic sampling. The strategic manholes in each zone were monitored daily and a grab sample collected to record explosivity, pH, temperature, color and solids content. Also, automatic composite sampling of the strategic manholes was completed on a quarterly basis as a method to identify illegal discharges that cannot be detected through grab sampling.

In 1992, MSD co-founded the Beargrass Creek Task Force, along with Louisville Mayor Jerry Abramson. The mission of the task force was to examine the resources of Beargrass Creek between Trevilian Way and Eastern Parkway (a reach that contained many CSOs), to access and suggest various methods which would best utilize and/or protect the resources of Beargrass Creek, and to offer suggestions and models as examples of ways people can protect and preserve their watersheds. Key recommendations from this 29-member task force included the following:

• Develop educational and interpretive materials on the cultural and natural history of Beargrass Creek
• Conduct annual clean sweaps on the Beargrass Creek to increase public awareness of the importance of creek protection
• Continue the MSD and USGS water quality monitoring program
• Work with MSD to establish goals and priorities to abate the water quality problem due to CSOs and stormwater runoff
• Identify critical areas suitable for demonstration for riparian recovery and bioengineering techniques
• Identify optimum areas along the creek for enhancing aquatic habitat and outline specific methods for doing so
• Designate and map wetlands along the creek
• Design a hiking trail from the Beargrass Creek State Preserve that would link North to the Ohio River and South to the headwaters

In 2002, MSD co-chaired a second Beargrass Creek Task Force, along with Louisville Mayor David Armstrong. The focus of this 31-member task force was to explore the potential for restoration of Beargrass Creek as an amenity for Louisville residents, visitors and wildlife. The target area extended from Towhead Island to the mouth of the creek at the Ohio River to the Beargrass Creek Flood Pumping Station. Successful projects in this area may be expanded along the reach of all three branches of the creek in the future. Key recommendations from this task force included the following:

• Create a Beargrass Creek boating channel from the Beargrass Creek Flood Pumping Station to its confluence with the Ohio River for small boats and private tour concessions
• Complete a marine engineering and feasibility study for safe boating harbor and Beargrass Creek boating channel
• Open the area up along Beargrass Creek to hikers and others who want to enjoy the natural setting by creating a trail system that connects with the Butchertown Greenway, Waterfront Park, and the bicycle and pedestrian way to be constructed along River Road
• Create a master plan for the entire Beargrass Creek Restoration Area including an extended trail system, nature preserve and picnic and other recreational area
• Design and construct, in partnership with MSD, a stream catchment system to collect solids, floatables and trash within the Beargrass Creek Restoration Area

Related Links

Prior to 1988 Initial CSO Program Efforts
1998 to 2002 CSO Program Efforts
2002 to July 2003 Holistic Watershed Approach

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