By: Mike MatichichVital statistics
WHO: Upper Occoquan Service Authority (UOSA), Centreville, Va.
SIZE OF TREATMENT WORKS: 54 mgd
SERVICE AREA POPULATION: 275,000
2010 OPERATING BUDGET, INCLUDING DEBT SERVICE: $61 million
CAPITAL BUDGET THROUGH 2021: $437 million
The Upper Occoquan Service Authority (UOSA) was formed in the 1970s to treat wastewater for four jurisdictions in the Occoquan Watershed, a rapidly growing suburban area 25 miles west of Washington, D.C. Originally 15 mgd, the facility was expanded in 1989, 1995, and 2005.
In addition to keeping the facility in sound working order, the operation's capital improvement program must address mandates that include further expansion of the delivery system and a nutrient-reduction program designed to protect and restore the Chesapeake Bay. With some assets nearing the end of their reliably useful lives, in 2008 the authority embarked on an asset management program to guide decisions regarding renewal and replacement.ASSET HEALTH AND OPERATIONAL CULTURE
Recognizing that tight economic times require investments to be highly targeted, managers adopted a risk-based approach for allocating resources. “The recession put significant strain on our capital budget,” says Executive Director Chuck Boepple. “We conducted these evaluations to make sure that we use our customers' dollars wisely, focusing renewal and replacement dollars on the assets whose failure would pose the greatest risks in accomplishing our mission.”
Documents such as Implementing Asset Management — A Practical Guide, published by the Association of Metropolitan Water Agencies, the National Association of Clean Water Agencies, and the Water Environment Federation in 2007, provide the starting point for assessing risk elements. But it's equally critical that the evaluation framework also represent the values, priorities, target service levels, and data situation of the specific agency.
We convened three workshops over two months with employees who were familiar with the authority's assets, mission, and vision. Using a 10-point scale, they identified individual components, assigned a weight to each, and defined how the contribution to failure should be scored for each asset or asset group.
Health & Safety and Permit Compliance were given the most weight in evaluating the consequence of failure. For the former, even minor injuries with no lost time were considered a moderate “consequence” outcome. For the latter, the asset had to cause chronic permit violation or result in pending enforcement action to receive the most severe rating.
As for assessing the likelihood of an asset failing, Physical Condition emerged as the most significant factor. But — and this is very important — Performance and Repair History were also regarded as significant considerations.
Because of the importance of physical condition to the risk equation, the authority assessed the condition of key assets. Over eight weeks, 1,912 pieces of mechanical and electrical equipment, pumps, and instrumentation, as well as facility infrastructure such as roofs and concrete, were inspected and rated. Six experienced operations employees evaluated the assets while a group of design engineers focused on plant infrastructure.
Before arriving onsite, authority managers gave the latter a list of assets from their enterprisewide JD Edwards maintenance management system. The evaluation team worked with authority employees to refine the database for field use and limit the evaluation to older assets. To more closely evaluate the condition of relevant architectural, structural, electrical, and building services components for the facilities being evaluated, though, several “new” assets, such as roofs, building skins, and HVAC equipment, were included as well.
The completed questionnaire was loaded onto handheld tablet computers for use by the field teams. The information gathered in the field was then loaded into our proprietary asset-condition evaluation system (ACES) software using the authority's existing equipment identification numbers so condition-assessment information could be transferred back into its maintenance management system upon project completion.