Procedure 730: Collection System Operations and Maintenance

Transcription

1 CITY OF GALT PUBLIC WORKS DEPARTMENT STANDARD OPERATING PROCEDURES Procedure 730: Collection System Operations and Maintenance Approval: Interim Director of Public Works Date CONTENTS A. Scope B. Objective C. Procedure 1. Mapping 2. Inspection 3. Routine Maintenance 4. Repair and Replacement 5. Automated Operations 6. Active Management 7. Capacity and Conveyance 8. Avoiding Sanitary Sewer Overflows A. Scope Public Works Department has developed the following procedures for operating and maintaining the sanitary sewer collection system within the City of Galt. B. Objective The purpose of this collection system operations and maintenance procedure is to detail the care of the collection portion of the City sanitary sewer system. The collection system collects and conveys sanitary sewage to the wastewater treatment plant. Proper care and maintenance can prevent or minimize the potential number and severity of sanitary sewer overflows. The objective is to conduct preventative maintenance activities to ensure that sewage is not spilled outside the system causing potential health concerns for humans and wildlife. Procedures once an overflow or spill has occurred are included in Procedure 720: Sanitary Sewer Overflow (SSO) Response. C. Procedure 1. Mapping Detailed maps of the collection system identifying sanitary sewer mains, manholes, and lift stations are on file at the Public Works Department located at 495 Industrial Drive. Maps of the system in convenient portable book sets have been issued to Streets Division and Utilities Division \\Msc1\pwdept\Administration\Procedures\Approved\730 Collection System Operations and Maintenance Rev doc Page 1

2 CITY OF GALT PUBLIC WORKS DEPARTMENT STANDARD OPERATING PROCEDURES personnel. As a minimum, the Streets Division Field Supervisor and the On-Call person shall carry one copy of these maps in their vehicle. These maps are divided into three sections that include: water distribution lines, sewer collection & transmission lines and stormwater collection lines. The City of Galt Maintenance Workers and System Operators use these maps frequently and are familiar with the format. Tab D of this procedure is a schematic of the force main sewer lines and lift station along McFarland Street. 2. Inspection Periodic Inspections with type of facility, frequency and sample forms. (a) Pump Stations Inspections: i. Daily (Operator): Wastewater pump station sites and electrical controls are inspected daily by certified wastewater system operators. ii. Weekly (Operator): Wet wells, hatch covers, float switches and pumps are visually inspected. iii. Semi-Annual (Electrical Contractor): Detailed inspection of the electrical motor control systems at the wastewater pump stations is performed semi-annually by a contracted equipment manufacturer Pump Stations Description: The wastewater pump stations are equipment with duplex pump controls that alternate the operation of two pumps at each station, providing backup and high flow capabilities. The submersible pumps are equipped with moisture and thermal sensors that alert operators to potential problems. Daily data records such as run hours and pump cycle also alert system operators to real or potential problems that could lead to pump repair or replacement. Wet well high level and low level alarms also alert operators to equipment problems. Wastewater system operators are trained to use voltage meters, amperage meters and ohmmeters to investigate and or troubleshoot controls and pump problems. The results of investigative troubleshooting determine when a component or piece of equipment will be repaired or replaced. Tab B of this document contains a four step inspection procedure and sample data sheet. (b) Gravity Sewer Lines Inspections: i. Quarterly: Manholes are checked for free flow of sewage and for presence of fats, oils and grease. ii. Annual: All manholes, manhole rings, lids, joint grouting, and pipe conditions are inspected and documented. Gravity Sewer Lines Description: The City has approximately 70 miles of underground lines ranging in size from 6 to 15 diameter. These gravity sewer lines are made of asbestos cement pipe (AC), \\Msc1\pwdept\Administration\Procedures\Approved\730 Collection System Operations and Maintenance Rev doc Page 2

3 CITY OF GALT PUBLIC WORKS DEPARTMENT STANDARD OPERATING PROCEDURES clay pipe and poly vinyl chloride pipe (pvc). Manholes are generally placed over the gravity sewer line at intervals of 300 feet. Manholes provide access to all gravity sewer lines for all inspections and maintenance operations. Tab C of this document contains a nine step inspection procedure. (c) Force Main Inspections: i. Monthly: Utility System Operators drive the three mile section of force main between the Live Oak Pump Station and the Wastewater Treatment Plant north of Twin Cities Road. Force Main Description: The force main is located along McFarland Street extending northwesterly, paralleling the Union Pacific Railroad, starting at A Street and terminating at the Wastewater Treatment Plant north of Twin Cities Road. The A Street Pump Station discharges into a 14 AC line that extends 1,800 feet to the Mc Farland Pump Station. Paralleling this section of 14 force main is an 8 by-pass line connected to the force main by gate valves located near the A Street Pump Station and McFarland Pump Station. The 14 force main continues from the McFarland Pump Station northerly to the Live Oak Pump Station. By-pass of this section of force main can be provided through a 12 welded pipe line paralleling this section of force main and connected by gate valves near Mc Farland Lift Station and Live Oak Lift Station. Tab D shows a map of the force main, by pass valves and pump stations. (d) Reports. Data and observations are recorded monthly. The report forms are reviewed and filed by the Division Supervisor. 3. Routine Maintenance (a) Schedule- See Tab A for Cleaning Schedule for Gravity Sewer Lines. (b) Gravity Sewer Lines and Pump Stations Quarterly Basis: Designated gravity sewer line sections are hydro flushed by the Streets Division with specialized high pressure equipment such as the Vac-Con combination unit or jetting unit. This equipment utilizes 2,500 PSI water pressure to clean and flush gravity lines. During gravity sewer line maintenance, the down stream pump stations are monitored and the wet wells are cleaned to remove grease or debris that has accumulated there as a result of hydro flushing. See Tab E for the Manual on hydro flush cleaning of small-diameter sewers for details on hydro equipment best practices. (c) Weekly: If repairs are needed, Service Order Requests are generated and are scheduled for correctional work. \\Msc1\pwdept\Administration\Procedures\Approved\730 Collection System Operations and Maintenance Rev doc Page 3

4 CITY OF GALT PUBLIC WORKS DEPARTMENT STANDARD OPERATING PROCEDURES 4. Repair and Replacement Provisions for repairing and replacing old, worn equipment. (a) Pump Station Repairs Each year a wastewater pump station is selected based on its age and condition for upgrade or replacement. At a minimum pump system upgrades include complete replacement of the electrical control system with modern equipment capable of communicating with supervisory control and data acquisition (SCADA) equipment. This work is performed by an outside contractor through the competitive bid process. Periodic malfunctions of electrical controls are investigated and repaired by trained Utility System Operators. Occasionally parts and or assistance are required from the control equipment manufacturer, TESCO of Sacramento. Tesco Controls, Inc (916) nd Avenue (916) fax Sacramento, CA The Utilities Division maintains an inventory of Flygt sewage pumps that are readily available to replace pumps as needed. The Utilities Division has a truck mounted hoist capable of removing all the wastewater pumps with the exception of Live Oak Lift Station. The 80 hp pumps at the Live Oak Pump Station are removed by Ken Gross Pump Service in Galt. Once removed, defective pumps are promptly delivered to the ITT Flygt Corporation in Fairfield for repair or replacement. Ken Gross Pump Service (209) W. Stockton Blvd. (209) fax Galt, CA ITT Flygt Corporation (707) A Chadbourne Road (707) fax Fairfield, CA (b) Gravity Sewer Line Repairs Gravity sewer line repairs are generally initiated from investigations on Service Order Requests from residents reporting problems they are experiencing or have observed. Streets Division will schedule and promptly make repairs or replacement of main lines, service laterals and manholes. Repairs beyond the capability of City crews are referred to the Engineering Division for project scheduling. (c) Force Main Repairs Occasionally Public Works staff will be called upon to repair the 16- inch force main between the Live Oak Lift Station and the Wastewater \\Msc1\pwdept\Administration\Procedures\Approved\730 Collection System Operations and Maintenance Rev doc Page 4

5 CITY OF GALT PUBLIC WORKS DEPARTMENT STANDARD OPERATING PROCEDURES Treatment Plant. Repairs along this two mile section of force main are difficult due to location, terrain and the large volume of wastewater in the line and headworks (over 107,000 gallons). There are two pump stations connected to the force main down stream of the Live Oak Lift Station. They include the McGee Correctional Training Center and the Vactor Receiving Station return pump station. The force main has no valves to divert the flow from these pump stations away from the damaged area. For the safety of those making the repairs, a lockout/tag out of Live Oak, McGee and Wastewater Treatment Plant pump stations is required. To facilitate the shut down of the McGee Training Center Pump Station City staff must call the Center s 24 hour emergency number (209) Identify yourself and ask that Greg Stinson, or someone from his operations staff, to lockout their lift station. Greg Stinson, the Correctional Center s Plant Manager, has on-call staff available after hours to respond to emergencies. The Correctional Center has approximately two to four hours of storage capacity in their collection system. To safely repair the force main, planning and co-ordination between the Streets Division, Wastewater System Operators and the McGee Correctional Center will be required. Therefore, if possible, temporarily contain or patch the leak until a full crew is available to make a permanent repair. Richard A. McGee Correctional Emergency (209) Training Center Greg Stinson (209) Twin Cities Road fax (209) Galt, CA Automated Operations At this time, wastewater pump and lift stations are inspected and adjusted manually on a daily basis. The pumps are automated in that they turn on and off based on wastewater levels detected in the wet wells. A Supervisory Control and Data Acquisition (SCADA) system design is being developed. It is anticipated that the first phase of the SCADA system will be installed in the summer of This system will allow remote monitoring and remote adjustment of the pump and lift stations. 6. Active Management The Streets Superintendent is responsible for actively managing the sewer laterals and mains. The Utilities Superintendent is responsible for \\Msc1\pwdept\Administration\Procedures\Approved\730 Collection System Operations and Maintenance Rev doc Page 5

6 CITY OF GALT PUBLIC WORKS DEPARTMENT STANDARD OPERATING PROCEDURES managing the wastewater pump/lift stations and their associated force mains. The Streets Superintendent will publish specific schedules and assign work to inspect, repair, and clean sewer mains. The Utilities Superintendent will publish specific schedules and assign work to ensure the proper and continuous operation of pump and lift stations. Often repairs and replacement of sewer system facilities requires the combined effort of both Public Works Divisions. 7. Capacity and Conveyance The City is currently completing a capacity study of the collection system. Once the study is complete, a capital plan to ensure adequate capacity throughout the collection system will be developed. The City of Galt Wastewater System Capacity Analysis draft was completed in April Once approved, it will become the basis for a program of projects and Capital Improvement Plan to ensure that system capacity keeps pace with new development. 8. Avoiding Sanitary Sewer Overflows (SSOs) (a) Procedures to minimize an SSO are contained in Procedure 720, Sanitary Sewer Overflow Response. (b) While total elimination of SSO s is not practicable, the maintenance and/or replacement of specific systems and lines described in the paragraphs above are intended to prevent most SSO s. Attachments Tab A Tab B Tab C Tab D Cleaning Schedule for Problem Sewers Inspection Checklist for Pump/Lift Station Inspection Checklist for Sewer Manhole/Main Force Main Schematic Diagram \\Msc1\pwdept\Administration\Procedures\Approved\730 Collection System Operations and Maintenance Rev doc Page 6

7 CITY OF GALT PUBLIC WORKS Focused Cleaning Schedule 90 Day (30 Day Highlited in Yellow) Quarterly Cleaning Schedule for Problem Areas Revised December 5, 2008 Location Date Crew Debris Type/Qty Ft Comments Mildred Ave. to Elm Ave to Oak Ave. to A Street. F Street & Third Street west to flushing branch clean out. Spruce Street from A St north to end of flushing branch clean out. 7th Street from C Street to D Street (grease). Alley between 6th, 7th, C Street, D Street (roots). Meladee Lane, Southdale Ct., and north to Chabolla lift station. G St. & Church St. west to alley, G St. north up the alley to E Alley between E St., F, St., 4th St, and 5th Street. Caroline and Chabolla Avenues. Wendy Hope Drive from Lincoln Way to Beno Court. Lincoln Way from wendy Hope to Myrtle. Carol Drive, Amador Avenue to Ayers Lane. Meadowview Subdivision (All). Eric Circle and easement south to Cindy Lane. \\Msc\PWDept\Utilities Services\Wastewater\Wastewater Collection System\Problem Areas

8 Delane Subdivision (All). Easement in back of 124 N. Lincoln Way north to Myrtle Ave. Maple Street alley from Caroline Ave. north to C Street. Franston Street, freeway fence north, west under Hwy 99 Camellia Easment from Terrace E Street from Lincoln to 4th, including alleys 100' Easement, Elm Onramp to Hwy 99 \\Msc\PWDept\Utilities Services\Wastewater\Wastewater Collection System\Problem Areas

9 Monthly Pump Station inspections, Operations and Maintenance Pump Station Name: Once Monthly Visual Inspection: Date: Operator: (A) Operational in Good condition (B) Operational in Poor condition, failure likely, schedule repairs or maintenance. (C)Non Operational, in need of prompt repair or replacement. (D) In need of weed abatement, grease removal, debris removal or cleaning Pump Station Component Check one, see description above A B C D Fences, gates, locks Panel A B C D Enclosures, Hatch Covers Control A B C D Circuits, Motor starters Bubbler System A B C D Float Switches Pumps A B C D submersible Pump Dry Well A B C D Provide Additional Information if needed Wet Wells A B C D Dry Wells A B C D Check Valves & Gate Valves A B C D Test and Record the condition of the following Monthly Pump Station Test Results Voltage Amperage Component L1 L2 L3 L1 L2 L3 Power Supply Functional Pump #1 Pump # 2 Bubbler Alarm and Panel Lights Dehumidifier

10 Dry well Sump pump Facility lights SCADA PLC Describe and report any problems observed during monitoring, operation Describe any needed repairs or maintenance Supervisor Certification: I, certify that I have reviewed and responded as needed according to the information provided in this report.

11 City of Galt Public Works Department Tab C Inspection Checklist for Sewer Manhole/Mainline Procedure 730 (Collection System Operations and Maintenance) Manhole / Mainline/ Lateral Inspection Procedure: 1. Perform a visual observation of the manhole, check for infiltration, root intrusion, debris on apron, debris in the troughs, grease build up, and cracks in the walls. Record all deficiencies, prepare Service Order Request and repair. 2. Inspect the manhole cover, and frame ring. Check to see if it at the proper elevation. Check for wear, fit, and proper type. Record all deficiencies, prepare Service Order Request and repair. 3. Inspect the grout joints and joint between the cone/grade rings and frame ring. Check for offset, steps, corrosion. Record all deficiencies, prepare Service Order Request and repair. 4. Inspect the inside drop structure (if applicable) for proper installation and function. Record all deficiencies, prepare Service Order Request and repair. 5. Look for any turbulence in the wastewater flow, signs inflow and/or infiltration, and listen for noises that may indicate such. 6. While performing routine high pressure water cleaning of the mainlines, check for proper flows, types and amount of debris removed, and possible stoppages. 7. If offset joints, cracked or broken pipe, or tapped in laterals in the mainlines are suspected, call in a contractor to CCTV the line. Record all deficiencies, prepare Service Order Request and repair. 8. If offset joints, cracked or broken pipe, in the laterals in the City s right of way are suspected, use City equipment to CCTV the line. Record all deficiencies, prepare Service Order Request and repair. 9. Dye testing and smoke testing will be performed to check sources of entry, proof of connections, and location of illegal connections, broken sewers and lost manholes. Page 1 of 1 5/2005

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