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

main sources of runoff into the collection system. Disconnecting storm drain cross
connections and eliminating other I/I sources will reduce peak flows into the system.
Costs associated with an I/I reduction program can vary greatly and are difficult to estimate
in the planning stage. Projects could range from closing open clean-outs to constructing
new storm drain pipelines to disconnect storm drain inlets from the sanitary sewer. To
develop the capital improvement projects associated with an I/I reduction program, we
assumed that roughly 25,000 feet (4.7 miles) of 24-inch diameter storm drain pipes would
be constructed through year 2030 and beyond. As with the sewer main rehabilitation and
replacement projects, the I/I reduction projects were distributed to the Aviation and Maritime
divisions based on the total length of pipe within each division.
9.2.5.5
Operations and Maintenance (Sewer Main Cleaning/CCTV)
CCTV inspection and surveys of selected sewers in the Port have revealed that there are
locations in the Port where sediment, FOG, large debris, and other materials have been
deposited. This is primarily a maintenance issue; however, a significant amount of sediment
build up or the presence of objects (e.g. concrete material) can reduce the capacity of a
sewer mains, which may clog sewers and result in SSOs. To reduce this potential, it is
recommended that the Port increase the cleaning frequency of those pipelines which have
been identified to have sediment deposits, root intrusions, or other maintenance issues.
As discussed in Chapter 5, a reasonable goal for the Port is to proactively clean roughly 20
percent of the total length of its gravity sewers 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.
It is further recommended that sewer mains and manholes receive a CCTV inspection
every ten (10) years, following cleaning. Since sewer cleaning should occur every 5 years
and CCTV work every 10 years, the CCTV work should happen every other occasion that a
sewer is cleaned. This will help to verify that the cleaning was properly performed and to
identify structural and condition problems in the sewers and manholes.
To develop the maintenance cost impacts associated with a sewer main cleaning/CCTV
program, we assumed that the Port would spend roughly $300,000 per year in the first,
third, and fifth round of sewer main cleaning and CCTV program. This equates to
$1,500,000 per phase for the first, third, and fifth round of sewer cleaning (Phase 1, 3, and
5). Because CCTV inspections are recommended on a ten (10) year schedule, we
assumed that the Port would spend roughly $200,000 per year for the second and fourth
rounds of sewer main cleaning (not accompanied by CCTV). This equates to $1,000,000
per phase for the second and fourth round of sewer cleaning (Phase 2 and 4). The
operations and maintenance costs were distributed to each division (e.g., Aviation,
Maritime, and Commercial/Real Estate) based on the total length of pipe within each. The
sewer cleaning and CCTV costs are included in Chapter 5 of the SSMP.
May 2010 9-12
pw://Carollo/Documents/Client/CA/Port of Oakland/8239A00/Deliverables/Ch09 (FinalA)