HSD’s Compliance with EPA’s Nine Minimum Controls Nine Minimum Controls HSD Compliance
1. Proper operation and regular maintenance programs for the sewer system and CSO’s. Proper operation is managed by HSD staff using SCADA and data collection programs. HSD maintains CSO outfalls and pump stations continuously, using state of the art Reliability-Centered Maintenance (RCM) procedures. Sewer Maintenance Dept. staff inspects sewers on a specified schedule and perform corrective actions when deficiencies are found.
2. Maximize use of collection system for storage. HSD emphasizes storage projects for CSO control. SCADA monitors outlying stations to maximize flows to the WWTP, and to store excess flows to the maximum allowable extent.
3. Review and modification of pretreatment requirements to ensure that CSO impacts are minimized. HSD’s Pretreatment Program issues permits that set limits on the chemical contents of industrial discharges. The program includes monitoring and permit enforcement, education, and technical assistance to businesses on appropriate waste pretreatment and disposal techniques.
4. Maximization of flow to wastewater treatment plant for treatment. SCADA is used to monitor flow to the HSD main treatment plant. Analyses for CSO control project alternatives include storage, and transfer to the wastewater treatment plant.
5. Elimination of CSO’s during dry weather. Operation and maintenance programs, as described for the first control, focus on preventing dry-weather overflows. The conveyance system is monitored through SCADA and direct observation; corrective action is taken immediately if a problem occurs. Equipment problems are immediately reviewed, with problem resolution aggressively pursued.
6. Control of solid and floatable materials in CSO’s. Control of solids and floatable material is accomplished using screen rakes at outlying station intakes. HSD’s screen rake maintenance program limits the introduction of solids and floatable materials to sewers. Also, the majority of floatables in the HSD system are captured in the large volume of wastewater transferred to the treatment plant before overflows occur. Unusual observations of the quantity of solids and floatables are acknowledged, investigated, and resolved.
7. Pollution prevention programs to reduce contaminants in CSO’s. HSD’s Pretreatment Program and has a major presence with local industries. Of the many program goals, reducing discharge to sewers that adversely impact the environment and the wastewater treatment processes is given priority. Educational materials on controlling trash disposal to sewers are a part of the larger public information program.
8. Public notification program to ensure that public receives adequate notice of CSO events and impacts. HSD operates a CSO Notification Program. This program includes the posting of signs at publicly accessible CSO locations, automated email notifications, a Web site, a brochure, and other public outreach activities.
9. Monitoring to effectively characterize CSO impacts and the efficiency of CSO controls. HSD monitors and records all CSO discharge volumes, precipitation data, and submits monthly reports to the Indiana Dept. of Environmental Management.