SANITARY SEWER CLEANING
The Northeast Public Sewer District (NPSD) is committed to providing reliable, uninterrupted sanitary
sewer service. Grease and other debris can form deposits on the internal wall of the sanitary sewer
pipe. Over time these deposits can cause blockages and backups in the sanitary sewer. Sanitary sewer
cleaning is a routine operation that results in a debris and blockage free gravity sanitary sewer system.
During this activity, high velocity water is sprayed against the internal pipe walls of the District's sanitary
sewer, systematically removing accumulated grease, debris and sediments.
Sanitary sewer cleaning operations will normally be conducted between the hours of 7 a.m. - 3 p.m.,
Monday through Friday. In addition to routine preventative maintenance, it may be necessary to
conduct emergency sewer cleaning operations at other times.
NPSD crews post signs at the entrances to neighborhoods approximately one week prior to conducting
preventative maintenance sanitary sewer cleaning operations.
How are the sanitary sewers cleaned? - NPSD Maintenance Department crews use a method called
"hydraulic jetting" to clean sanitary sewers. The activity consists of running a hose with a jet nozzle
attached through the sanitary sewer. Entry to the sanitary sewer is made via a manhole structure.
These manhole structures are evident in yards and streets by the cast iron lids visible at the ground
surface. Once the jet nozzle and hose are fed into the sewer pressurized water is applied. Water exiting
the jet nozzle at high velocity forces the jet nozzle/hose assembly down the sewer pipe, cleaning the
sewer as it goes. Once the jet nozzle/hose assembly reaches the next manhole structure the hose is
reeled back mechanically cleaning the sewer pipe a second time.
What can I expect when sanitary sewer cleaning is taking place in my neighborhood? - The District's
sanitary sewers are located in the street right-of-away or dedicated utility easements. These easements
may run along the front, side or back of residential and commercial properties depending on the layout
and construction of the sanitary sewer lines serving the area. NPSD crews will use these easements to
access the sanitary sewer lines and associated manholes. Hydraulic jet cleaning of each section of
sewer line may take a few minutes up to an hour. Depending on the distance between the sanitary
sewer and the house or building, a rumbling or water running noise may be heard. The action of the
jet nozzle moving past the house or building lateral connection may cause a slight negative pressure
(vacuum). This vacuum may momentarily pull down the water level in toilets and plumbing fixture
traps. The house or building plumbing vent should prevent water from completely being pulled from
toilets and plumbing fixture traps.
Why is the house or building plumbing vent important during sanitary sewer cleaning operations - The
house or building plumbing vent has a number of important functions. First, it allows air in drain lines
to be displaced so that water will flow down from toilets, sinks and other plumbing fixtures to the house
or building main drain line and lateral connection to the District's mainline sanitary sewer. Second, it
provides ventilation of the sanitary sewer helping to maintain the wastewater "fresh" and less odorous.
Wastewater flowing in the sanitary sewer creates a slight pressure drop that draws air down through
the vent and into the mainline sanitary sewer. Third, the vent along with the plumbing fixtures "traps"
prevent odors and dangerous sewer gases from traveling from the sanitary sewer, up the house or
building lateral connection and into the house or building. Fourth, the vent reliefs any pressure drop
(vacuum) that may be created during sanitary sewer cleaning operations. Odors and other plumbing problems can occur if the house or building vent(s) are not properly installed and maintained. Vents
can get clogged with bird or insect nests, leaves and debris in the house or building plumbing. Vents
can also be installed incorrectly or in the wrong location(s).
What causes odors in my house or building immediately after cleaning of the sanitary sewer? - The most
likely cause of odors inside the house or building is that one or more of the plumbing fixture traps is
dry. It may have been dry prior to the sanitary sewer cleaning or the water normally in the trap may
have been drawn out if the house or building vent is not operating properly. Odors problem in the house
or building can be easily remedied by pouring a quart of water down each plumbing fixture to refill the
trap. If the odor does not go away after refilling the plumbing fixture traps, there may be a more serious
problem with the house or building plumbing. A licensed plumber should be consulted.
What causes the water in my house or building toilet to bubble, burp or overflow? - Similar to the cause
of odors, water burping from the toilet is caused by an improperly operating plumbing vent. A licensed
plumber can diagnose the problem and make recommendations. In the meantime, the problem can be
temporarily solved by opening the clean out cap to your house or building lateral. Most houses and
building have a clean out located on the side or front of the structure approximately three feet from the
wall. The open clean out acts as an additional vent for the house or building plumbing. Opening the
clean out should only be a temporary remedial until a licensed plumber can make permanent repairs.
Open clean out allow rodents, debris and stormwater to enter the sanitary sewer.
Does the District's program of cleaning the sanitary sewer system include my house or building lateral
connection? - The hydraulic jetting of the District's sanitary sewers does partially clean the house or
building lateral as the jet nozzle moves past the connection point to the sanitary sewer, but is not design
to clean the lateral. House or building lateral maintenance is the responsibility of the property owner.