Sanitary Sewer Maintenance Policy
The purpose of this policy is to maintain the City's sanitary sewer system to prevent backups and to extend the life of the system.
The City has 180 miles of public sanitary sewer mains, 4,800 manholes and 24 lift stations within its collective system. Procedures identified in this policy are intended to provide effective and efficient maintenance to its sanitary sewer system by evaluating political, social, safety and economic concerns. The City has developed and implemented this policy that takes into consideration public safety, the City's budget and personnel, environmental concerns and the cost of implementation versus benefit achieved. The City will use its employees and equipment and/or private contractors to provide this service.
While the City intends to meet the guidelines established in this policy, there may be times when this is not feasible. Issues including, but not limited, budget constraints, critical equipment failure or weather and other emergencies may prevent the City from meeting the guidelines established herein. The Public Works Director or Utility Superintendent may override provisions established within this policy. Deviations from these goals will be documented.
The City will use this policy to guide any sanitary sewer maintenance activities to be provided by a contractor or a party other than the City.
Routine Maintenance & Inspection Goals
Responsibility: The City will maintain the components of the public sanitary sewer system. This includes sanitary sewer mains, manholes, lift stations and other components. Private property owners are responsible for the maintenance and repair of sanitary sewer components from their property up to and including the connection to the public system (City Code Section 28-91).
The City's goal is to clean the sanitary sewer system mains every 3 to 5 years. Pipe size, material age and condition will be assessed by qualified staff and will be considered determining factors for cleaning schedule.
The equipment used to perform maintenance will depend upon availability and effectiveness as determined by qualified staff. Equipment includes: Jet machine, Jet/Vac Machine (both with various saw and nozzle attachments), 1,200-gallon water tank for high-volume flushing, Easement Machine, and various hand tools as needed.
The City's goal is to inspect approximately one-twelfth of the public mains per year. Any sewer mains located within a street maintenance project area will be inspected before and after such a project. Sanitary mains in a new development must be televised before said mains are turned over to the City. Television inspection may also be used to inspect the system where there are possible problems. In addition, the City may require any main near a construction site to be televised before and after the construction (i.e., near blasting, digging, pile driving, etc.).
Visual recordings of sewer main televising will be required of any vendor performing this service for the City. A written report summarizing and interpreting the findings of the televising will also be required. These records will be kept by the City for a minimum of 12 years.
Sanitary sewer mains and facilities that require more frequent maintenance due to age, condition, flow rates, types of waste (i.e. grease, industrial discharges, etc.) will be documented in an easily accessible book or digitized record. Frequency of inspection and/or cleaning will be determined by qualified staff. If repair or improvements have been made on a problem area, staff will reassess if said main or facility may be removed from problem list and will be documented as such.
The City maintains 24 lift stations using specific maintenance that is reasonable and recommended. The number of lift stations, location, date of installation/rehab and specifications of each lift station is kept on record. Maintenance for each lift station is kept on record. Maintenance for each lift station is reflected in Standard Operating Procedures (SOP) and Standard Maintenance Procedures (SMP).
Components of SOP & SMP
- Easy availability of original manuals with manufacturers' recommended maintenance schedules for all lift station equipment.
- Operating procedures for manipulating pump operations (manually or automatically)
- Setting wet well operating levels to maximize efficiency of pump start/stops
- Cleaning wet wells
- Conducting draw down tests
- Regular rotation of lead, lag, and backup pumps (done automatically with alternators)
- Regular inspections of lift station, alarm/monitoring systems (SCADA), and electrical components
- Maintenance of operation logs and general records for all lift station activities, including inspections
- Clean/inspect force mains
- Identify problem areas/components
Inflow & Infiltration
Inflow and infiltration occur when clear water gets into the sanitary sewer system. This may occur through cracks or leaks in the sewer pipes and manholes or through sump pumps and roof drains illegally connected to the sanitary sewer system. Inflow and infiltration can lead to backups, overflows and unnecessary and expensive treatment of clear water.
City employees and/or private contractors will periodically inspect manholes to identify any that contribute to this problem. Sanitary sewer mains will be maintained and inspected pursuant to the City's Sanitary Sewer Maintenance Policy.
Components of SMP
- Sump pump inspections
- Non-infiltrating manhole covers
- Rebuilding and (re)sealing manholes
- Replacing and/or lining of mains
- Coordinating with City Health Department and businesses to keep grease, industrial wastes, etc. from entering City mains
Personnel Responsibilities & Requirements
Exercise of Professional Judgment: It is expected that City employees, in accordance with their job duties and responsibilities, will exercise their professional judgment in the implementation of this policy. City employees will exercise their discretion when considering, but not limited to: Public and employee safety, potential for damage to public and private property, and economic and environmental concerns.
Training & Education
The City will provide training to employees responsible for maintenance and emergency response to issues with the sanitary system. Training of employees will include education necessary to earn and maintain appropriate operator certifications. Training will also address standard operating procedures, proper use of equipment, emergency response and other topics required by state and federal regulatory agencies.
The City of Edina will document all of its inspection and maintenance activities and emergency responses for its sanitary sewer system. The City will also document circumstances that limit or prevent its ability to comply with this policy. Records will be periodically reviewed and assessed for determining future goals.
The City will periodically provide its residents with information related to the care and maintenance of both public and private sanitary sewer systems. Included in this information will be the steps for notifying the City about backups, items not to be flushed or put down the drain, homeowner backup insurance, and other topics related to sanitary sewer maintenance.