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White Paper
City of O’Fallon Infrastructure Maintenance Requirements
February 6, 2012
The City of O’Fallon, Illinois has annual requirements for maintenance, repair, and upgrade of components of its infrastructure to keep them in operational condition. This paper outlines the costs of those infrastructure requirements based on existing assets as of the date of this paper. The components of City infrastructure for the purpose of this paper are buildings. roads, sidewalks, water mains, water storage structures, water booster pump stations, sanitary sewer mains, sanitary sewer lift stations, wastewater (sanitary) treatment facilities, stormwater mains, stormwater detention features, and improved open stormwater conveyance features.
Roads – The City currently has approximately 22,500,000 square feet of paved roadway surface. Assuming that every 15 years some major form of maintenance is needed to keep the pavement suitable for traffic, approximately 1,500,000 square feet of pavement needs to be repaired or upgraded every year. Based on actual CY2011 costs, approximately $1.64 is required to mill 3 inches of the existing surface & overlay an asphaltic concrete (AC) pavement with a new 3” surface. While that is not the only solution for asphaltic surface rehabilitation and is not a methodology of extending the life of Portland cement concrete (PCC) pavement’s life, it provides a starting point to understand the scope and cost of pavement rehabilitation. “It gets us in the ballpark.” Using $1.64
per square foot of pavement as an average price, for the 15-year rehabilitation the cost of pavement maintenance, prior to the consideration of inflation, additional pavement to maintain due to further development, and the need to re-build failed or failing pavement sections, is approximately $2,460,000 per year. Unfortunately, roads after about 60 years of service can no longer be reasonably improved by surface or spot repair methodologies. In O’Fallon, oil and chip streets are a good example of this problem. In 2011, the City reconstructed a portion of Central Drive, and accepted bids for the reconstruction of Milburn School Road from Simmons to Merriam Parkway. The costs were extremely close for both streets on a square footage basis, about $16.00 per square foot for reconstruction of curbs, stormwater and pavement. So, if roadways were reconstructed on a 60-year cycle, the yearly cost for the 375,000 square feet of roadway needing
reconstruction to meet that cycle, discounting the $16.00 per square foot by the $1.64 per square foot that would be a part of the 15-year cycle maintenance cost discussed above, the approximate cost for reconstruction would be $5,385,000 per year.
Sidewalks – Staff is still working on an accurate inventory of sidewalks in the City, so for this paper, assume that for each mile of pavement the City has to maintain, sidewalk along at least one side of that roadway. Since the City has approximately 140 miles of roadway to maintain, that would mean the City has approximately 140 miles of sidewalk to be maintain – 739,200 feet. Assuming sidewalk has a useful life of 100 years (once again a pretty good number to get us in the ballpark), 1% of the length will need to be replaced every year. At $26.20 per lineal foot, based on actual CY2011 costs, prior to the consideration of inflation or future additional sidewalk to maintain due to further development, funding would need to be approximately $193,670 per year.
Water Mains – The City currently has approximately 1,420,000 feet of water main. Assuming that every 100 years, the average section of water distribution piping and valves will need replacement, disregarding the need to replace piping due to a requirement for additional transmission capacity, approximately 14,200 feet of pipe needs to be replaced every year. A fairly representative project carried out in early 2011 along Scott-Troy Road, although it did not have many utility conflicts like work in the middle of the City, cost approximately $35 per foot. With that as an average price per foot for the cost of water line, valve and fire hydrant replacement, prior to the consideration of inflation and the further addition of water lines due to additional development, approximately $497,000 per year
needs to be applied to water line rehabilitation.
Water Storage – The City currently has 5 million gallons of water storage capacity. Assume that every 60 years, the average water storage tank needs replacement or complete rebuild that will likely cost the equivalent of a new one today. Additionally, assume the cost to build new or rebuild is $1.25 per gallon, based recently completed tanks along Kyle and Pausch Roads. The cost of water storage tank replacement/rehabilitation, prior to the consideration of inflation and the additional need for storage due to additional development, should be approximately $105,000 per year.
Water Booster Pump Stations – The City currently has 2 booster pump stations. The City just recently replaced the pump station near French Village in Fairview Heights which was nearly 50 years old at the time of replacement. Assume the cost to build a new one or refurbish one will be about the $1,000,000 recently spent. The cost of water booster pump station replacements/refurbishment, prior to the consideration of inflation and the additional need for water pumping due to additional development, is approximately $40,000 per year based on the 2 pump stations the City now has.
Sanitary Sewer Mains – The City currently has approximately 620,000 feet of wastewater main. Assume that every 60 years, the average section of wastewater main will need major rehabilitation/ replacement, disregarding the need to replace piping due to the requirement for additional transmission capacity, approximately 10,000 feet of pipe with its manholes needs to be replaced every year. Recent projects (2010 & 2011) indicate that the cost can be approximately $120 per foot or higher. So, the cost or investment in wastewater line replacement, prior to the consideration of inflation and the further addition of wastewater mains due to additional development, should be approximately $1,200,000 per year.
Saniatry Sewer Lift Stations – The City currently has 14 lift stations. Best data would suggest that a lift station with its pumps and controls is good for about 25 years. The last lift station built in the City cost approximately $100,000 to build, and complete rebuild at 25 years is not likely any less expensive. Therefore, the cost or investment in sanitary sewer or wastewater lift station replacements, prior to the consideration of inflation and the additional need for list stations due to additional development, should be approximately $56,000 per year.
Wastewater (Sanitary Sewage) Treatment Plant – The City’s current wastewater facility was upgraded in 1997 with anticipated life span of 15 years until another major upgrade was needed. Based on a recent analysis, that appears to have been a good estimate. The cost of the 1997 upgrade was $6,000,000. The estimate for the next upgrade currently stands at $9,000,000 without expansion of capacity or capability due to the ever more stringent limits on discharges from wastewater treatment plants. As such an upgrade every 15 years seems reasonable at this point. Therefore, the investment in plant upgrades, prior to the consideration of inflation and the additional need for treatment due to additional development, should be approximately $600,000 per year.
Stormwater Infrastructure – The City currently has approximately 60,000 feet of stormwater main and numerous inlets. To address the problems with the infrastructure, the ditches that provide surface drainage, City detention ponds, and stream reaches affected by runoff from the City, a Stormwater Action Committee was formed as part of an effort to promote a stormwater utility. Although the utility was never formed, the research that went into presentations to the committee was invaluable on getting a handle on the requirements for a quality stormwater program. The Committee recommended that $880,000 per year be spent on stormwater maintenance and capital improvements.
Facilities – A rather simple rule of thumb for facilities is that 2% of their value needs to be re-invested every year in them to ensure their upkeep beyond daily maintenance such as janitorial. The value of facilities that Public Works currently has repair and upkeep responsibilities for is penciled in at $6,500,000 based on insurance documents. These facilities are City Hall, Old City Hall, 200 S. Lincoln, Old Library, Bus Depot (Chamber of Commerce Offices) and Caboose. Two percent (2%) of that value equates to $130,000 per year.
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