Maintenance Gets a Lift

Transcription

1 Maintenance Gets a Lift Hot Springs, Arkansas Employs Asset Management to Lift Station Maintenance and Saves Hundreds of Thousands of Dollars Aaron Stallmann, PE Garver AAStallmann@GarverUSA.corn ABSTRACT The city of Hot Springs, Arkansas has an extremely unique wastewater collection system comprised of more than 3,200 lift stations. The majority of the gravity and pressure collection system is more than 20 years old and age is taking a toll on the performance of the overall system. Due to reoccurring sanitary sewer overflows, the Arkansas Department of Environmental Quality issued a Consent Administrative Order in August of 2008 requiring the city to eliminate all dry-weather-related sanitary sewer overflows by January 2011 and all wetweather-related sanitary sewer overflows by January Hot Springs assembled a team of consultants and staff to address the collection system issues that contribute to this problem and determine the most cost-effective path forward to meet the requirements of the order. The city's renewed commitment to asset management has been a key item in achieving these goals. The end result is a unique and robust city implemented asset management program as well as a complete program for renewal and replacement of the infrastructure. This system has been developed and implemented as a way to save real money on the road to compliance with a consent administrative order. KEYWORDS: Asset management, collection system, lift station, sanitary sewer overflow, consent administrative order Introduction The city of Hot Springs, Arkansas (CHS) is facing tremendous challenges regarding the condition and capacity of its wastewater collection system. The CHS collection system is quite unique with more than 3,200 lift stations ranging from simplex grinder pumps to 290 horsepower triplex lift stations. A majority of the sanitary sewer infrastructure was constructed 20 or more years ago. The Arkansas Department of Environmental Quality issued a Consent Administrative Order (CAO) in August 2008 requiring CHS to eliminate all dry-weather-related sanitary sewer overflows (SSO) by January 2011 and all wet-weather-related SSOs by January 2018.

2 To comply with the deadlines outlined in the CAO, CHS began by hiring consultants to evaluate the system's condition and capacity. One team focused on the lift stations and force mains while another focused on the gravity mains and manholes. This discussion spotlights the efforts associated with evaluating the lift stations and the issues that were noted and addressed to work toward meeting the CAO deadlines. As a result of these efforts, CHS has implemented new concepts and ideas to increase efficiency and develop a more proactive approach to managing its lift station system instead of merely reacting to a problem when it occurs. Specifically, this discussion will include information about the following topics: Background information describing the regulatory requirements that prompted these efforts Background information on the CHS collection system Methodology used to evaluate the lift stations Common issues discovered during the evaluations and proposed solutions Challenges associated with designing and implementing the recommended solutions Hot Springs unique and robust approach to asset management in the lift station group Preventative maintenance versus repair decision making process Overview of current status and progress toward the goals Methodology Not long after the team began working to identify issues and develop solutions to the lift station system, CHS hired a new manager for the lift station group. This change in management brought a different approach to maintaining and operating the pressure side of the sewer collection system. Information gathered during onsite visual inspections of the lift stations was combined with institutional knowledge from long-time staff members to develop files for each location. The files include details about the station, including pump make and model, historical maintenance information, regular maintenance items, etc. The file system has been used to implement a new work order system that focuses on maintaining the stations instead of only performing emergency repairs. The work order keeps the stations on a regularly scheduled maintenance program and prompts dispatchers to order necessary parts prior to the scheduled maintenance date. The lift station group has also established an inventory of spare parts that is indexed to allow for expedited repairs when necessary. The chart below illustrates how this new system has impacted the workload distribution for the lift station team at CHS. In 2008, basically zero time was spent on maintenance. Over the past few years, the team has seen a moderate decrease in the amount of time necessary for emergency repairs as the amount of time spent on scheduled maintenance has increased. The city staff has

3 also developed a sense of pride and ownership in the collection system that has increased awareness of potential problems and boosted morale. Hot Springs, Arkansas Sewer Lift Station Man Hours U Repairs El Preventative Maintenance ris t 300 o z 0 es 21XJ 1SU 1UU 50 U Results As CHS continues to work toward its goals and regulatory requirements, it is anticipated the two fields will converge until there is an acceptable amount of repair and maintenance throughout the lift station system. Over the past five years, the CHS lift station group has not added any fulltime positions; however, they have been able to increase the amount of maintenance on lift stations by approximately 120 hours per week. This is equivalent to nearly three full-time positions CHS is able to benefit from without spending any additional money on staff compensation. At a cost of $60 per hour, this savings translates into approximately $375,000 per year.

4 2008 Lift Station Group Man Hours 2012 Lift Station Group Man Hours f4 Repairs M Preventative Maintenance Repairs Preventative Ma intenance I Table 1. Cost Savings due to Preventative Maintenance Program Year Repair Man Hours (per week) PM Man Hours (per week) Total Hours Hourly Rate Amount of Annual PM Realized w/o Additional Staff $60 $ $60 $374,000 The CHS lift station group uses a work order system to practice a higher level of asset management than they were capable of in the past. On a regular basis, the software generates an order form that allows the staff to have the correct parts and equipment on hand to perform upcoming lift station maintenance. Once maintenance is performed at a particular site, the event is filed with the location and is accessible for future reference. This enables the staff to document ongoing problems at particular lift stations. Without recognizing an ongoing problem, the staff may have continued to simply repair the broken parts, but with a documented history of issues, the staff can focus on determining the root cause of specific problems. This saves money in repair and replacement costs and saves time for the staff by eliminating repeat service calls. Conclusion Hot Springs has faced many challenges while working through the process of complying with the CAO. When facing a situation like this, success depends on being able to assemble a competent and cohesive team to attack the problems, establish a reliable asset management system to allow for tracking and accountability, and work to find solutions that maximize efforts and dollars spent. Much of CHS's progress toward meeting the milestones in their CAO can be attributed to adhering to these key directives.

5 ftrm pproach to Lift Station es Hund edsfoof Thousandsi, Aaron Stallmann, P WEFTEC 2013 October 8,2013

6

7 res /MVP' xtremely unique stem Legend o Minor Pump Station Major Pump Station City Limits 74 Major Lift Stations Over 3,200 Grinders!

8

9 Lift static = ua ab is a collaborativ Garver and Hot Springs staff met to prioritize the evaluation isequen arver evaluated mechani lectrical, and capacity re tern F r. c Design and construction projects were prioritized on information discovers during the evaluations

10 11\111\\ \111% ( IIIII11IIIIII re

11 corn ted 4 major Lift Station n pr ti_acts totaling over $3MM

12

13 HotZpring s has improve sset management effective ass City Work used sparin Work Orde System organ izatio f Staff and perational hilosophy 2011-Current Utilize City Works for asse management t efficiently maintain spare parts inventor

14 The results of Hot Springs 's commitment are evident through significant savings PM Repair cu w 300 a

15 The results or t S are evident f gh gs s commitment gnificant savings 2008 $ $60 $374,400

16

17 Aaron Stallmann PE inweesams4 '''rinrver 501)