Port-Wide Sewer System Management Plan(SSMP) - Port of Oakland

London Square along Embarcadero. These pipes discharge either into the City collection
system or directly into the EBMUD interceptor that runs parallel to Embarcadero.
5.3 PORT PREVENTATIVE MAINTENANCE PLAN
This section summarizes the Port’s existing preventative maintenance program.
Recommendations are provided, as appropriate, in order to reduce the potential for SSOs
in the Port and to better comply with the GWDRs.
5.3.1 Preventative Maintenance and Inspection Activity
Preventative maintenance activities can include some of the following:
a. Periodic cleaning of sewer lines is essential for proper operation. Higher
frequency cleaning might be necessary in those areas with a history of
stoppage due to debris and fats, oils, and grease. There are many methods to
clean sewer lines including flushing, rodding, or high velocity jet cleaning.
Hydroflush or other hydraulic cleaning of gravity sewers is the most commonly
used method to clean sewers. Mechanical cleaning (e.g. rodding machine)
might be more effective than hydraulic cleaning in certain sewer conditions.
Note that mechanical cleaning can only be applied to rigid pipe material such as
vitrified clay, concrete, or reinforced concrete pipe.
b. Root control in areas that are known to have recurring blockage, SSOs, or
premature structural damage due to root intrusion.
c. Investigation and resolution of customer complaints.
d. Scheduled cleaning of force mains.
e. Closed-circuit television (CCTV) inspection of the sewers and visual inspections
of manholes.
The Port currently performs sanitary sewer cleaning on an “as needed” basis (i.e., when a
blockage or overflow occurs). Maintenance activities related to the gravity sewer system,
therefore, are almost exclusively “corrective” in nature. While this strategy may have proven
sufficient in the past, it is recommended that the Port begin to take a more preventative
approach with regard to sewer line cleaning. A reasonable goal for the Port is to proactively
clean roughly 20 percent of the total length of its gravity sewers (in both Aviation and
Maritime) each year, thus providing a rotation in which every sewer main is cleaned at least
once every five (5) years. This equates to roughly 7 miles of sewer mains cleaned annually.
Figure 5.2 identifies a potential sewer main cleaning rotation to achieve the desired
cleaning schedule.
Hydraulic cleaning equipment is the most frequently used piece of equipment applied for
cleaning sewers less than or equal to 18-inches in diameter (WERF, 2003). The sewers are
cleaned through a targeted application of high pressure water. These high pressure/velocity
machines are used to open stoppages, remove grease, clean lines of debris, and wash
manholes and wet wells. A variety of water tank sizes, pressure output, and nozzle
configurations are available for both truck and trailer mounted equipment.
May 2010 5-9
pw://Carollo/Documents/Client/CA/Port of Oakland/8239A00/Deliverables/Ch05 (FinalA)