### MEMORANDUM

TO: Airport Deicing Administrative Record

FROM: Mark Briggs, ERG

DATE: July 26, 2010

SUBJECT: Estimated Capital and O&M Costs for Additional Stormwater Piping

This memorandum estimates both the capital and annual operating and maintenance (O&M) costs for an airport to install additional stormw ater collection and conveyance piping. Costs have been developed for transfer of stormwater from deicing areas to either on-site storage and treatment facilities, or to the local sanitary sewer system for discharge to a Public Owned

Treatment Works.

Costing Approach

Piping costs to transfer collected stormwater to ei ther on-site treatment or to the local sanitary sewer collection system will vary for each airpor t. Variables which could impact costs include existing subsurface utilities, soil types, eleva tion changes, and anticip ated peak precipitation events. Because each of these variables are airpor t specific and the detail s are not available to EPA, ERG assumed costs would be estimated fo r each airport to constr uct 10,000 liner feet of new subsurface stormwater conveyance piping from various areas around the airport. The estimated length of piping is based on comment s received on the proposed deicing rule. According to the comments from the airline industr y, piping lengths will be nearly 10,000 feet to accommodate the entire length of the runway.

Capital and Operating Cost for a Stormwater Conveyance Piping System

Elements of a new stormwater piping system include subsurface concrete piping, manholes and catch basins, a lift station and associated pum ps, and knife gates through out the system to

control the direction of flow. ER G obtained 2002 costs for individua l elements within the system from RSMeans Building Construction Cost Data 1 , and adjusted the costs to 2006 dollars. Cost factors for plumbing and site work were added to the direct costs based on the Department of Defense MILCON estimating procedures 2 to obtain total installed dire ct costs. Indirect costs for engineering, permits, scheduling, performance bonds , and contractor markups were added to the

total installed direct costs. Table 2 shows the estimated inst alled capital cost for 10,000 linear feet of a new stormwater conveyance piping system is approximately $1,141,000.

1 RS Means Construction Cost Data,68th Annual Edition, 2010, RSMeans Company, Inc, Construction Publishers and

Consultants.

2 U.S. Department of Defense (USDOD) . 2001. Military Cons truction Program 1391Memorandum July 26, 2010 Page 2

Annual operating and maintenance costs for the pi ping and conveyance system include periodic inspection to verify integrity of the piping syst em. To estimate labor costs for TV inspection of the 18” sewer, ERG made a conservative assumption that an airport would inspect 20 percent of the storm sewer system annually (2,000 linear f eet), at a rate of $1,350 per day (2006 basis). Based on engineering experience, a sewer TV crew of two to three persons can inspect approximately 500 feet of piping per day. At a rate of $1,350/day, the annual airport inspection cost would be $5,400.

Summary

The costs included in this memorandum will be used in the airport deicing cost model to estimate costs by airport for additional stormwater pipi ng. Costs for additional piping will be combined with other costs for collection and recovery including block-and-pump and above-ground storage

tanks.MemorandumJuly 26, 2010Page 3Table 2. Estimated Installed Capital Cost for 10,000 Linear Feet of a Stormwater Conveyance SystemDescriptionUnitsQuantityUnit CostTotal CostTrench excavation. Assume 6' deep, 3/8 CY backhoe. Assume trench is 4' wide and 10,000 feet perairportaCubic yard 8889 $7.50 $59,081Backfill and compact trench, compact in 6" lifts vibrate tamp, 300' haul.aCubic yard 8889 $4.83 $38,048Piping. Assume concrete, 18" diameter.aLinear Feet 10000 $35.00 $310,175Manholes, assume concrete, 6' deep.Manholes spaced at 100' intervalsaEach 100 $1,550 $137,363Manhole frames and covers, heavy traffic, 24” dia.aEach 100 $325 $28,802Subtotal Direct Cost:$573,496Plumbinga(connectors, extra labor, etc.) % ofsubtotal direct cost 32.7 $187,524Sitework (clearing, grading, surveying)a% of subtotal direct cost 14 $80,286Total Direct Cost:$841,280Engineeringb% of total direct cost 8 $67,302Permitsb% of total direct cost 2 $16,826Schedulingb% of total direct cost 0.8 $6,730Performance bondsb% of total direct cost 2.5 $21,032Insurance (risk, equipment floater, public liability)b% of total direct cost 2.3 $19,349Contractor markup (handling, procuring, subcontracting, change orders, etc.)b% of total direct cost 10 $84,128Overhead and profitb% of total direct cost 10 $84,128Total Indirect Cost:$299,496Total Cost:$1,140,775a – RS Means Heavy Construction Cost Data, 64th Edition, 2010.b – U.S. Department of Defense (USDOD).2001. Military Construction Program 1391.