CITY COUNCIL MEETING AGENDA PACKET

Element 4 – Operations and Maintenance Program City of Pleasanton Sewer System Management Plan, July 2025 19 4.2.1: Gravity Mains Cleaning: Sewer collection systems require continuous maintenance to ensure proper function/performance. In addition to common maintenance defects (roots, debris, grease, etc.), items not intended for the sewer system (non-dispersible wipes, kitty litter, floss, etc.) can be introduced at any time, which makes regular cleaning a high priority. Gravity mains will be cleaned on a 7-year frequency cycle and in a systematic manner to ensure flow efficiency. Gravity main segments will be cleaned from the downstream manhole to the upstream manhole whenever possible. Exceptions can be made in some cases: (1) there are no lateral connections on the gravity main being cleaned, or (2) a forward-cleaning nozzle is being used. The City will primarily use in-house resources to perform cleaning for piping 15-inch and smaller. However, until a resource study is completed (see Section 4.5) and needed employees are identified and hired, contract services will be used to supplement staff. For large diameter sewers (greater than 15-inch diameter) and siphons, all cleaning will be performed by contract services. Inspection: CCTV inspection of gravity mains will follow cleaning and occur on a 7-year frequency cycle. The City will primarily use in-house resources to perform inspection for piping 15-inch and smaller. However, until a resource study is completed (see Section 4.5) and needed employees are identified and hired, contract services will be used to supplement staff. For large diameter sewers (greater than 15-inch diameter) and siphons, all inspections will be performed by contract services. CCTV inspections are intended to evaluate system performance and drive much of the maintenance and repair activities needed to properly operate the sewer collection system. Defects and other findings will be coded using the National Association of Sewer Service Companies (NASSCO), Pipeline Assessment Certification Program (PACP) and Pioneer software. CCTV inspections will also occur as a follow-up to SSOs to determine the cause of the SSO and to ensure the affected pipe is performing adequately. This inspection will be performed as soon as possible after the SSO event. This inspection will be used to verify findings when reporting to CIWQS and will help determine maintenance and repair activities to prevent reoccurrence of the SSO. Hot Spots: The City keeps a hot spot list, which are sewer pipe segments that have been identified by staff as requiring high frequency cleaning. When placed on the hot spot list, the pipe segment is assigned a maintenance frequency (i.e., monthly, quarterly, biannually, annually, etc.) and maintenance method (i.e., appropriate nozzle type). The pipe segment is also evaluated for feasibility, cost, and benefit of repair to determine if and when is the most appropriate time to implement improvements and remove the segment from the hot spot list. Root Control: Gravity main segments to be included in the root control program are generally informed by the results of the cleaning and inspection program. Gravity main segments that Page 274 of 323