Laserfiche WebLink
7 of Santa Ana Section 4: Operations and Maintenance Pro <br />4.2.2 Preventative Maintenance <br />The City's sewer collection system Operations and Maintenance Program consists of critical proactive, <br />preventive and corrective measures for the City's gravity sewer system and lift stations. The details of the City's <br />O&M Program are summarized below with further detail and specific procedures set forth in the City's Sewer <br />System Operations and Maintenance Manual. <br />4.2.2.1 Gravity Mains <br />The City of Santa Ana cleans the majority of sewer system on an 18 month cycle, and corresponding areas that <br />are similar. However, the City does collect field observations and data during routine maintenance activities, <br />which factor into maintenance frequencies. This utilization and analysis of field data will allow the City to <br />optimize maintenance activities throughout the sewer system. This process will result in more sections of <br />gravity pipelines being cleaned less frequently than the traditional 18 month cycle. <br />The City has identified areas of the collection system that require more frequent cleaning— known as enhanced <br />maintenance locations (EMLs) — which are cleaned on a monthly or quarterly interval. EMLs include, but are <br />not limited to, inverted siphons that run under flood control channels and commercial areas with a high density <br />of food service establishments. <br />The City executes the collection system maintenance program with two sewer cleaning trucks, each staffed <br />with a two -man crew. The gravity mains within the City are divided into two discrete zones with one crew <br />assigned to each zone. In general, the gravity mains are cleaned in a Northeast to Southwesterly direction, <br />following the natural gravity flow of the sewer system. <br />To control root growth within the sewer system, the City performs as -needed root control activities. The root <br />control activities include the use of foaming that is approved by the U.S. Environmental Protection Agency for <br />this use. CCTV inspections are often used to evaluate the root growth and determine the appropriate mitigation <br />measures for each stretch of impacted sewer mainlines. <br />Sewer maintenance activities are scheduled and tracked using the GIS-based computerized maintenance <br />management system (CMMS). For each line segment cleaned, the maintenance crews complete a report <br />detailing the date, time, location, and key observations during the maintenance activities. Field observations <br />include assessment of the type (e.g., roots, FOG, debris) and quantity (e.g., light, medium, and heavy) of <br />materials removed during the line cleaning process. These observations are analyzed and factor into <br />determinations of maintenance frequency adjustments. Additionally, observations of "heavy" accumulation are <br />prioritized for CCTV inspection and/or other source control actions. <br />4.2.2.2 Lift Station/Force Mains <br />In addition to the crews maintaining the gravity sewer system, the City's Water Production staff supports <br />maintenance of the two sewer lift stations and the force mains are cleaned as needed. Water Production <br />Operators are cross -trained to assist with the maintenance of these pump systems. Maintenance activities <br />include weekly inspections of each lift station, along with periodic equipment servicing consistent with <br />equipment manufacturer's recommendations and industry standards/best practices. <br />4.2.3 Rehabilitation and Replacement <br />A comprehensive condition assessment of the City's entire sewer system was completed in 2010. The City <br />assigned each sewer segment a structural severity rating, consistent with industry standard National <br />April 2020 4-3 <br />19F-21 <br />