Water Utilities

• High-pressure washer/vacuum trucks for cleaning and scouring debris, cutting roots, and chemically treating root intrusion and grease build-up. 

• CCTV camera vans that allow us to remotely inspect sewer mains, and in some instances customer service laterals for defects and failures. It also allows us to inspect new installations prior to acceptance into the city system.

Rehabilitation of the underground infrastructure is an important part of Sewer Maintenance. Since much of the system was installed as long ago as the late 1890’s, some of the main lines were constructed of materials such as clay, cast iron and concrete, and these lines are beginning to fail from long-term wear and tear. All new installations require longer lasting PVC or ductile iron with a protective liner, and are designed and installed to provide an extended service life. Long-term plans call for the on-going repair, rehabilitation and replacement of the sewer mains that are structurally inferior or damaged.

Sewer lift station operation, maintenance and repairs is a vital function in the proper operation of the sewer collection system. With thirty-five separate sites to maintain, the Sewer Lift Division stays busy! Each lift station site is specifically designed for a set of operating conditions that are peculiar to that location, and each is fitted with at least two sets of pumps and motors, operating controls with alternating relays, and level controls to monitor on/off cycles. Motor sizes range from 2 H.P. to 100 H.P., pump sizes range from 3-inch to 10-inch, some are above-ground suction lift and some are submersible and are underground and out of sight. Some stations are actually fitted with pumps that pump into a second pump to achieve high rates of flow at high pressures!

Another important job of the Sewer Maintenance division is the identification and elimination of infiltration and inflow through an Infiltration/Inflow Program. This program works to maintain and improve the efficiency of the City’s sanitary sewer collection system and wastewater treatment plant, and to prevent sewer overflow and backups.

What is Infiltration/Inflow (I/I)?
Infiltration occurs when groundwater enters the sewer system through cracks, holes, faulty connections, or other openings. Inflow occurs when surface water such as storm water enters the sewer collection system through rain gutter connections, holes in manhole covers, illegal plumbing connections, or other defects. The sanitary sewer collection system and treatment plant have a maximum flow capacity of wastewater that can be handled. I/I, which is essentially clean water, takes up this capacity and can result in sewer overflows into streets and waterways, backups into homes, and unnecessary costs for treatment of this water. It can even lead to unnecessary expansion of the treatment plant to handle the extra capacity. Unless identified and corrected, these costs could get passed on to the consumer.

How do we identify sources of I/I?
A Sewer System Evaluation Survey (SSES) involves inspection of the sewer system using several methods to identify sources of I/I:

• Visual inspection-accessible pipes, gutter and plumbing connections, and manholes for faults and defects.
• Smoke testing, where non-toxic smoke is pumped into sewer lines at manhole openings. Its reappearance above ground indicates points of I/I. These points can be on public property, such as along street cracks or around manholes, or on private property such as house foundations or in yards where sewer lines lay underground. If smoke shows up inside of a house or other structure it is an indication of faulty plumbing, and a plumber should be contacted to make necessary repairs. The rule of thumb is, if smoke can get into a structure then so can deadly sewer gas!
• TV inspection, where closed circuit camera equipment (CCTV) is used to do internal pipe inspections.
• Dye testing, where dyed water is used at suspected I/I sources. Dyed water is poured in ditches or sink holes where I/I is suspected to occur, and the source is confirmed if the dye appears in the sewer system.
  

Sources of I/I are also sometimes identified when sewer backups or overflows bring attention to the part of the system. The purpose of the SSES is to reduce these incidences by finding sources before they cause a problem.

How do we repair I/I sources?
Repair techniques include:

• Sealing manhole walls with cements or epoxies.
• Trenchless technology systems such as relining pipes with resin-infused liners, or by pipe-bursting where a new pipe is pulled inside of the existing, damaged pipe.
• Repairing or replacing a single point or even an entire mainline section.
• Replacing or reseating manhole frames or lids.
• Requiring property owners to repair or replace faulty service laterals.
• Disconnecting roof drains, area drains and rain gutters.
  
  

Each home or commercial building has a separate connection to the public sanitary sewer main called a sewer lateral. It is the property owner’s responsibility to maintain and repair their own sewer lateral from the house up to the point of connection with the public sanitary sewer main.

The following are helpful hints to keeping your sewer lines clear:

• Don’t flush or throw kitty litter, egg shells, coffee grounds, motor oil, lard, cooking grease, or any substance other than sanitary waste or normal wash water down the drain. Grease from cooking and powered laundry detergent are the two agents that we have found to cause the most problems in customer service laterals, and ultimately in the main collection system. Both will resolidify and cause lumps and blockages.
• Use baskets or strainers in the sink drains to catch food scraps or other solids.
• Scrape grease and food scraps from plates, pots and pans, utensils and grill and dispose of in the garbage.
• Pour grease into a container and let solidify. Then discard in your trash receptacle. Grease can build up in sewer lines and restrict the flow or cause blockages, and can ultimately force wastewater up onto streets or even your homes.
• Be cautious of chemicals or additives that claim to dissolve grease, these may not be effective or may allow grease to resolidify further downstream.
• Clogged sewer pipes on your property can also cost you money in plumbing repair bills.
• The following some of the products that are considered household hazardous chemicals and should never be flushed down the sewer: pesticides, nail polish, oven cleaners, spot removers, vehicle fuel, oil and grease, fertilizer, rodent poison, weed killer, paint, varnish, stripper or thinners or battery fluids. These require disposal at the Household Hazardous Waste Collection day held each year by the City. Call the Public Works Department at 318-242-7703 for more information.
  

Wastewater brochure

Household hazardous waste brochure