05 - Sewer Hotspot Update
Costa Mesa Sanitary District
Memorandum
To:
Board of Directors
From:
Scott Carroll, General Manager
Date:
April 15, 2014
Subject: Sewer Hotspot Update
Summary
Sewer hotspots are line segments that require higher cleaning frequencies (more than
once a year) due to large grease accumulation, structural defects, and/or root intrusion. In
the beginning of 2011, the District had 95 hotspot locations. As of today, the District has
successfully reduced the number of hotspot locations to 41 due to several actions
performed by staff that includes repairing structural defects, installing short liners and top
hat liners to prevent root intrusion and disseminating FOG awareness.
Staff Recommendation
That the Board of Directors receive and file the report.
Analysis
Every quarter
(once every three months), District staff and consultant Environmental Engineering &
Contracting (EEC) analyze the causes for labeling line segments as hot spots and then the
group will determine a course of action to remedy line segments and remove them from
the hot spot list. Sample courses of action include installing cured-in-place short liners and
top hats to eliminate root intrusion, repairing line segments and replacing pipes that have
sags.
The 41 hot spot locations are broken down into the following categories along with the
number of locations for each category:
Grease 27
Structural 3
Structural w/ roots 1
the environment by providing solid waste and sewer collection se
www.cmsdca.gov
Board of Directors
April 15, 2014
Page 2 of 3
Structural w/ grease 3
Roots 6
Debris 1
Recently, after conducting an RFP with five companies for Project #197-B, the District
$111,000
awarded a contract to Sancon Engineering for to perform full length lining using
cured-in-
$106,000
Estimate is . The incidental work includes installing top hats and rechanneling
one sewer manhole. When this project is complete three hotspot locations will be
removed from the list, which will reduce the total locations to 38, thus achieving Strategic
Goal 1.3.
On July 31, 2013, staff presented to the Board an analysis of the practicality of having
permanent hotspot locations. As an example, sags cause hot spots because grease, grit
and solids settle out and become hardened, but to repair the sag the entire sag area has
to be excavated, removed, and the line replaced. Replacing the average sag with new
pipe typically exceeds $100,000 but cleaning the sag four times a year is a very small cost
by comparison. Staff concluded that it is practical to have eleven permanent locations due
to grease and structural defects. Staff believes it is more cost effective to continue with
high frequency cleaning than it is to repair the defects. To date, staff has identified seven
permanent hotspot locations. Staff will continue working on reducing the remaining 31
hotspot locations.
Strategic Plan Element & Goal
This item complies with Strategic Element 1.0., Sewer Infrastructure and Strategic Goal
No. 1.3., Reduce Hot Spot locations to less than 40.
Legal Review
Not applicable
Environmental Review
Repairs or reconstruction of sewer lines to remove hotspots is categorically exempt under
the California Environmental Quality Act (CEQA) (Public Resources Code Section 21000
publicly-
Financial Review
Funds are budgeted appropriately to maintain the hot spot locations. As more hot spot
locations are reduced the staff hours spent on hot spots can be shifted to providing annual
cleaning services.
In addition, there is adequate funding in the CIP budget to complete Project #197-B.
Board of Directors
April 15, 2014
Page 3 of 3
Public Notice Process
Copies of this report are on file and will be included with the entire agenda packet for the
April 15, 2014 Board of Directors study session
website.
Alternative Actions
1. Direct staff to report back with more information.