SERVICES DEPUTY CITY MANAGER I ADMINISTRATIVE SERVICES PUBLIC WORKS ClOY ENGINEER DIRECTOR DIRECTOR PROJECT & CONSTRUCTION ENGINEERING

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1 Operation and Maintenance This section summarizes key operation and maintenance aspects of the City's sewer system. Included in this section is a description of the wastewater system personnel, instrumentation and controls, the preventative maintenance program, the monitoring program, record keeping, and recommended 0 & M improvements. Wastewater System Personnel The City has several staff members devoted to operating and managing the wastewater system. City departments that are involved in managing the wastewater system include Operations and Maintenance, Engineering, and Finance. Figure 8-1 shows the organization structure for managing and operating the wastewater system. ClOY AOMIN/INTERGOVERNMENTA SERVICES DEPUTY CITY I ADMINISTRATIVE SERVICES PUBLIC WORKS ClOY ENGINEER DIRECTOR DIRECTOR - WASTEWATER PROJECT & CONSTRUCTION ENGINEERING I FINANCE DIV. CIVIL ENGINEER IJI I CIVIL ENGINEER II = CIVil ENGINEER I ACCOUNTANT ENGINEERING TECH II UTILITIES = WASTEWATER WASTEWATER OPERATIONS MAINTENANCE SUPEFlVISOR SUPERVISOR I-- PRETREATMENT COORDINATOR t: GENERAL CAAFTSWORKER I-- PREiAEAl'MENT INSPECTOR FACILITIES CRAFrSWORKEA I-- LAB TECHNICtAN II UT ILITIES CAAFTSWORKER r- LAB TECHNICIAN 1 t-- PlANT OPERATOR,-, PLANT OPERATOR -IN-TRAINING Figure 8-1. Richland Wastewater Utility Organization Chart P;/251461Rjchland General Sewer Plan Update Page 8-1

2 Instrumentation and Controls A SCADA system allows the City to operate its wastewater system more efficiently and respond to problems quickly. The SCADA system sends information from the wastewater treatment plant and the lift stations to the City's main control center in the Operations Building. A description of the instrumentation and controls at both the WWTF and the lift stations is provided below. Wastewater Treatment Facility Controls The WWTF utilizes a distributed intelligence control system (Wonderware). The control system consists of (I) a central computer system located in the Operations Building, (2) programmable logic controllers (PLCs) in individual process buildings, and (3) microprocessor-based process or instrumentation loop controllers in the process buildings. The central computer system allows the operator to monitor and control all the plant's process drive motors from the computer in the Operations Building. The central computer system also provides data logging, generation of graphs and reports. The PLCs are located in the local control panels of the various process buildings. The PLCs replace control relays and also receive analog data from a variety of sensing devices. The PLCs are programmed to control their respective treatment processes within set parameters. Analog data for more complex control loops, such as the aeration system, are fed into a process loop controller. This device compares a number of analog signals (dissolved oxygen concentration, air flow rates, etc.), then modulates air flow control valves as dictated by control logic. The process loop controller communicates directly with the central computer system but not with the PLCs. The control system is designed so that the treatment plant will continue to operate without interruption if the central computer system fails. In this case the PLCs and local control panel in each building (except the activated sludge pump station) provide control capabilities identical to those of the central computer. Process motors also have field control stations mounted adjacent to them. A final level of backup is provided by manual switches on each motor control center (MCC) starter cubicle. Lift Station Controls The central computer system is also used to monitor lift stations throughout the City using remote telemetry units. These units relay data to the computer on the operation of each lift station. These units are read-only and are not used to control lift station equipment from the wastewater plant. Page 8-2 P:125146IRichland General Sewer Plan Update

3 Operation and Maintenance Preventative Maintenance A preventative maintenance program is important to ensure that the system continues to operate smoothly and quality service continues to be provided to the City's customers. Preventative maintenance may include visual inspections by maintenance personnel, closed circuit television (CCTV) inspections, and regular cleanings. Preventative maintenance of each of the facilities is described in more detail below. Wastewater Treatment Facility The process loop controller has an elapsed time hour meter for each of the drives under its control. The computer has access to the elapsed times shown on these meters. The computer can be programmed with a list of all equipment and the specific maintenance requirements for each item. Changes can be made as required to incorporate modifications in maintenance requirements or to add new equipment. Upon demand, the operator will request a scheduled maintenance printout. At this instruction, the computer will scan its files, read the PLC hour meters, and compare maintenance requirements with the operating time and elapsed time since previous maintenance. A printout will then be generated showing all equipment due for scheduled maintenance. The printout will contain specific tasks to be performed. After the scheduled maintenance has been performed, the console operator will make entries into the computer recording the completion of those tasks. The computer will then make the appropriate changes in its database so that those items will not appear until their next scheduled date. Any items not entered as having been performed will automatically appear on subsequent scheduled maintenance printouts until they are entered as having been performed. Lift Stations Lift stations are checked weekly by operations staff to assure all equipment is operating as designed. Multi-rangers, bubbler systems, and pumps, are checked visually and operated to make sure they are functioning properly. Lubrication of equipment and exercising of valves is done on a monthly basis. Maintenance crews pump out wet wells of grease and floating material weekly and check equipment monthly. Force Mains, Trunks, and Laterals The preventative maintenance program for the sewer collection system is a continual, ongoing program that is manned by six craft workers and one maintenance supervisor. Each two-man crew is responsible for various functions in maintaining the system. One crew is assigned to a hydraulic jet cleaning truck that cleans City sewer lines as scheduled on a preventative maintenance list. The second two-man jet truck crew also performs preventative maintenance duties from a scheduled list. This crew cleans lines by hydraulic jetting, hydraulic sawing, power rodding, and hand rodding. These crews P:/251461Richland Genera1 Sewer Plan Update Page 8-3

4 also make repairs to sewer lines, manholes, and clean-outs as needed. Both crews also respond to emergency sewer back-up calls as needed. Between 2001 and 2003, the average length of City sewer line cleaned per year was 880,000 feet. The third crew runs the CCTV inspection program and inspects all of the sewer lines in the collection system that are 6 inches in diameter or larger using a portable TV camera mounted on rubber tracks. Required inspection is performed on all old sewer lines, newly constructed lines, and lines where problems have been reported. All inspections are captured on videotape, and all information obtained during inspection is input into the Hansen sewer maintenance software program. The CCTV crew prints out work orders and schedules maintenance based on its inspection findings. In 200 I, the CCTV crew inspected 95,000 feet of sewer lines. Monitoring Program Flow monitoring of the collection system for III and flow is currently being performed. R.W. Beck and the City of Richland completed the last III study in The current NPDES permit requires the City to complete an III study before the submittal for permit renewal. The City purchased three new, portable flow meters, and the City plans to place the meters throughout the collection system to monitor flows and check for III. This will be done to determine when and where problems exist or may occur in the future. Record Keeping and Reporting The Wastewater Maintenance Division uses the Hansen software for sewer maintenance reporting and record keeping. All maintenance work performed on the collection system, including new construction, labeling manholes and clean-outs on drawings, CCTV inspections, preventative maintenance work, repairs, and sewer back-up problems is recorded by this software. All CCTV inspections are also recorded on videotapes that are stored and recorded. Most problems and customer complaints are received by telephone. When a complaint, such as a sewer back -up, is first received, office staff makes sure that the Maintenance Supervisor is notified immediately either by radio or cell phone. The supervisor then contacts a crew in the field to respond. Crews respond to these calls within 30 minutes of receiving them.. If the supervisor can not be contacted, then the crews are called directly. Office personnel enter the information from all problem calls received into the City's quality service system. The quality service system then prints out a job ticket with an assigned work order number. This information is stored in the computer system, and the printed job tickets are stored for up to a year at the WWTF. Page 8-4 P: Richland General Sewer Plan Update

5 Recommended 0 & M Improvements Operation and Maintenance City staff identified several operation and maintenance improvements, which are listed below. Replace current, high-maintenance, poor efficiency digester mix pumps with a new mixing strategy that involves either different types of pumps or different mixing equipment (e.g., turbine mixers). Improve the electrical panel equipment maintenance/cleaning procedures in each building for increased reliability and safety. Initiate computerized maintenance system for plant repair and equipment maintenance history and parts inventory. Change heatinglheater arrangement in Solids Handling Building for improved maintenance access and efficiency. Modify/improve grit handling system to produce drier solids for disposal. Make necessary repairs to aerators and aerator electrical outlets at the sludge lagoon to enable year round lagoon operation. Replace dissolved air floatation tanks with a gravity belt thickener and blend tank for increased solids concentration. Instal1/build a sewer decant pad in back of treatment plant for dumping vactor truck wastes collected from sewer manholes and lift stations. Improve preventive maintenance (PM) scheduling by making more use of equipment run time instead of calendar days as a basis for PM scheduling. Train more craft workers on treatment plant maintenance versus collection system maintenance as part of succession planning and backup help. P: Richland General Sewer Plan Update Page 8-5