City of Morgan Hill Sewer System Master Plan 2017

x RP-P3 : Replace the existing 6-inch gravity sewer along Main Avenue from 120 feet east of Hale Avenue to 300 feet east of Hale Avenue. This improvement is meant to mitigate the existing sag in the gravity main. The existing sag prevents the flushing of the gravity main. x RP-P4 : Replace the existing 6-inch gravity sewer along Monterey Road from 3rd Street to 4th Street. This improvement is meant to mitigate. This improvement is meant to mitigate the existing sag in the gravity main that could cause potential traffic hazard. x RP-P5 : Replace the existing 6-inch gravity sewer along Right of Way east of Manor Court to 450 feet west of Monterey Road and Bisceglia Avenue. This improvement is meant to mitigate the existing sag in the gravity main preventing access. 7.6 INFILTRATION AND INFLOW INVESTIGATION IMPROVEMENTS City staff suspect there may be infiltration and inflow related deficiencies in the sewer collection system. As such, this master plan recommends a future Infiltration and Inflow (I/I) Investigation and Reduction program be initiated to identify, track, and mitigate I/I deficiencies. Should I/I defects be found and mitigated, it will reduce peak flow events during the wet weather season, help mitigate sanitary sewer overflows, and reduce the need for costly improvements to increase capacity in the collection system and the treatment plant. The following elements may be included in a potential future I/I study: x Pre-rehabilitation flow monitoring x Basin delineation for high priority basins As part of this Master Plan, preliminary I/I mitigation projects were identified from the City’s existing CCTV data. While these projects were included in the condition assessment improvements discussed in a previous section, they are documented on Figure 7.7 and Figure 7.8 and individually in this section should City staff choose to prioritize these improvements before the condition assessment groupings. These improvements include the following: x INI-P1 : This improvement consists in 50 feet of trenchless rehabilitation for the 8-inch gravity main located along Llagas Road from 80 feet east of Hale Avenue to 20 feet east of Hale Avenue. x INI-P2 : This improvement consists in 300 feet of trenchless rehabilitation for the 8-inch gravity main located along the Llagas Road from Fox Hollow Drive to Murphy Springs Drive. x CCTV for high priority basins x Rehabilitation pilot projects x Hydraulic Model Calibration x Post rehabilitation flow monitoring

August 2017

7-16

City of Morgan Hill Sewer System Master Plan