MEMORANDUM 

TO: Brian D’Amico, EPA EAD

FROM: Mark Briggs, ERG

DATE: November 16, 2011

SUBJECT: Estimated Capital and O&M Costs for a Plug-and-Pump Collection System 

This memorandum documents the methodology that EPA used to estimate both the capital and annual 

operating and maintenance (O&M) costs for an airport to implement a plug and pump collection system 

for stormwater contaminated with aircraft deicing fluid (ADF). EPA used the same approach to estimate 

costs for the final rule as for the proposed rule. EPA did not receive any comments or additional data 

following the proposal on its plug and pump costing methodology or underlying data. EPA developed 

this memo to more clearly explain its approach. 

As a point of clarification, this memo describes EPA’s costing approach for the components of plug and 

pump including GCVs. Costing for other components of the technology basis such as additional piping, 

land, and equalization/storage and treatment are detailed in separate memos. 

Plug-and-Pump Technology Description

The primary objective in employing plug and pump systems is to intercept deicing stormwater close to 

the source, often using existing storm sewers for temporary inline storage. This approach facilitates costefficient collection of deicing contaminated stormwater and can improve the economy of glycol 

treatment/recovery systems. The plug and pump collection system utilizes the airports existing storm 

water collection system infrastructure in combination with glycol collection vehicles (GCVs) to contain 

and collect ADF contaminated stormwater. The plug and pump system operates by placing either 

temporary inflatable balloons or storm sewer shutoff valves in the existing storm sewer system. During 

deicing events, the balloons are inflated and storm sewer shutoff valves are closed, trapping the ADF 

contaminated stormwater in the collection system. Vacuum trucks pump the trapped contaminated 

stormwater from the storm sewer system and transport the liquid to on-site storage. In addition, catch 

basin inserts can be placed into manholes to collect ADF contaminated stormwater. The typical plug and 

pump system commonly uses GCVs to sweep ADF contaminated stormwater from the gate, ramp and 

apron area surfaces following application. The glycol recovery vehicles deliver the ADF contaminated 

stormwater to on-site storage/equalization. Blocking mechanisms are generally opened or removed 

during non-deicing periods to allow normal drainage of non-impacted stormwater (DCN ACRP Footnote 

24). 

System Components

Plug and pump system design depends on the airport configuration. Generally, the existing storm sewer 

system piping is used to contain ADF until it can be removed by a GCV, vacuum truck, or is pumped 

directly to a storage/equalization tank. For airports that do not have sufficient storm sewer piping in 

deicing areas, additional piping may be required. Sewer balloons, catch basin inserts, and diversion 

valves, and real-time monitoring can be installed in the system to contain ADF and allow release of 

uncontaminated stormwater following a deicing event. Permanent or temporary storage/equalization 
Memorandum 

November 16, 2011 

Page 2 of 5 

tanks are also required to store the glycol contaminated stormwater until either recycling or treatment. 

Sewer ballons, catch basins, and diversion valves are described in more detail below. 

Sewer Balloons 

Sewer balloons are inflatable bladders and can be installed almost anywhere there is access to the storm 

sewer. Sewer balloons can be inflated with either air or water and provide a simple and effective storm 

sewer pipe plug. Sewer balloons do require secure anchoring within the storm sewer system to prevent 

them from being lost beyond the immediate manhole area 

Catch Basin Inserts 

Catch basin inserts provide a physical barrier for containing deicing stormwater on the surface of the 

apron to allow time for collection or for testing prior to its release. Inserts are typically installed in catch 

basins that receive surface drainage from aircraft deicing areas and are capable of being readily closed 

prior to the start of the deicing event and opened subsequently to allow clean aircraft deicing laden 

stormwater to enter the storm sewer system. 

Different types of physical barriers are available. The simplest method consists of a molded plastic dropin panel with a depression in the bottom that serves as a sump. These have limited practicality because 

they require that the storm grate be lifted to install or remove the barrier. A more sophisticated and 

practical approach employs a metal sump installed under a catch basin grate and fitted with a butterfly 

valve that can be operated with a T-handle from the surface. Inserts typically remain closed during the 

deicing event, although many operators keep them closed longer to prevent dry weather discharges of 

deicer. 

Diversion Valves 

Diversion valves provide flexibility in managing stormwater with varying deicer concentrations. 

Diversion valves may be used to contain water in the collection system for plug and pump, or direct 

stormwater to one of several destinations, including treatment, storage, or discharge. Installations vary in 

complexity from manually operated valves to automated diversion systems that operate based on realtime monitoring. Manual diversion valves are typically operated based on deicing conditions or weather 

observations (e.g., containment or diversion to storage during deicing events and to surface water between 

events). Automated valves may allow flows to be managed more precisely during deicing events. These 

valves may be actuated by a supervisory control and data acquisition (SCADA) system, which may make 

diversion decisions based on online monitoring or management system information. Several valve types 

are suitable for use in deicing stormwater containment systems. In general, resilient gate valves or plug 

valves are preferred. Ultimately, any valve used for deicing stormwater must have zero leakage and be 

chemically compatible. 

Simple, manual diversion systems are appropriate for airports with relatively simple deicer management 

systems that are operated infrequently or do not require changes often, and airports that collect and 

discharge all deicing stormwater to a single destination. More sophisticated and costly automated 

approaches may be justified at airports with management systems where operation can be optimized using 

concentration-based flow segregation. Automatic valves are often used in applications requiring frequent 

diversion. 

Cost Methodology

Where EPA determined an airport would not meet a 40% collection requirement based on its 

existing technologies, EPA estimated both capital and annual operating and maintenance (O&M) 
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November 16, 2011 

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costs for such airports to employ plug-and-pump collection (the technology basis for the 40% 

collection requirement). The following describes how EPA estimated costs for such airports. 

Available Data 

Although EPA requested capital and operating cost data for all types of ADF collection and 

treatment technologies in the Airport Questionnaire (DCN AD00354), no cost data were 

provided regarding plug and pump. In addition, the airport industry did not provide any 

additional cost information during the comment period on the proposed airport deicing rule. 

Instead, one airport provided capital cost information on their plug and pump type collection 

system (General Mitchell International Airport - Milwaukee) during the site visit, and one 

airport provided information on their annual cost for plug and pump (Minneapolis-St. Paul 

International Airport -Minneapolis) during subsequent contacts. 

Capital Costs 

Data to estimate capital costs was provided by General Mitchell Airport (MKE). During the 

2005 deicing season, MKE controlled deicing contaminated stormwater from three outfalls. To 

perform the collection, MKE employed eight (8) sewer balloons, four (4) storm sewer shutoff 

valves at, and two (2) catch basin inserts (DCN AD00772). In addition, this airport utilized two 

(2) GCVs for ancillary glycol collection; one is a traditional truck-based GCV and the other is a 

GCV unit that is towed behind a tractor. MKE estimated capital cost for its plug-and-pump 

system (including the GCVs) to be approximately $790,000, see Table 1. 

Table 1. Estimated Capital Cost for the Block-and-Pump System in Milwaukee 

Equipment 

Number in 

Service 

Unit Cost 

(2006$) 

Total Capital 

Cost (2006 $) 

GCVs 2 $360,0001 $720,000 

Sewer balloons 8 $4,4503 $35,600 

Shut-off valves 4 $8,1002 $32,400 

Catch basin inserts 2 $1,4001 $2,800 

Total: $790,200 

1. Workshop: Best Management Practices for Airport Deicing Stormwater 

2. RSMeans Heavy Construction Cost Data, 2002 (24” Diameter Knife Gates with Handwheel) 

3. Includes 24” diameter balloon, hot tapping insert system, inflation hose, and controllers and valves from 

Peterson Products, Co., Fredonia, Wisconsin. 

To use this information to estimate capital costs for other airports, EPA normalized the MKE 

capital costs based on the number of deicing outfalls, see Table 2. EPA assumed that the number of 

deicing outfalls would relate to the number of areas where aircraft deicing occurs, so that in 

general an airport that has a greater number of discontiguous deicing areas will have a greater 

number of deicing outfalls. EPA estimated that more deicing areas would indicate the need for 

additional costs associated with removing ADF from those areas 

As shown in Table 2, capital costs to install a plug and pump system that will achieve 40% collection 

approximate $263,400 per deicing outfall . EPA attempted to provide conservative cost estimates, so if a 
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November 16, 2011 

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model facility’s baseline level of collection (see DCN ADF Collection) was greater than 0% but less than 

40%, EPA applied full capital costs as if no collection technologies had been employed at baseline. EPA 

took this approach because it does not have data to estimate incremental costs for a facility with some 

baseline collection system that does not conform to plug and pump to upgrade to a system that does 

conform with the plug and pump technology that forms the basis of a 40% collection requirement. This 

approach likely overestimates costs for some facilities. 

Table 2. Normalized Capital and Operating Costs for the Block-and-Pump Collection System 

Airport Deicing 

Outfalls 

Total Capital 

Cost (2006 $) 

Capital 

Cost / 

Outfall 

($/outfall) 

Milwaukee 3 $790,000 $263,400 

Operating & Maintenance Costs 

Data to estimate O&M costs was provided by Milwaykee Airport (MKE). As reported by in an 

e-mail to EPA (DCN Furhman email), MSP controlled deicing contaminated stormwater 

discharges from five (5) outfalls (DCN AD00793). MSP contracts out its collection to a third 

party. To perform the collection, the third party provides all of the equipment and employs plug 

and pump operations including plugging the associated drainage pipes and pumping out these 

drains with dedicated vacuum pumping trucks. The plug and pump system at MSP does not, 

however, include GCVs. MSP reported that the annual cost for this service are approximately 

$1,300,0001. Due to the limited cost data on plug and pump technologies provided by airports in 

the questionnaire responses, EPA used the annualized cost information from MSP to estimate O 

and M costs associated with plug and pump operation. 

Clearly, MSP’s annual costs overstates operation and maintenance costs alone because MSP’s 

costs also include amortization of the equipment and other none operation and maintenance 

related costs. Therefore, while the MSP costs do not include operating and maintaining GCVs, 

EPA concludes applying the MSP costs is appropriate and will not underestimate anuual 

operation and maintenance costs associated with the plug and pump system that forms the basis 

of 40% collection because operation and maintenance of GCVs are likely less than the 

equipment amortization costs or something like that. 

To estimate the O&M costs for other airports for plug and pump collection, again EPA 

normalized the MSP O and M costs based on the number of deicing outfalls. See Table 3. As 

shown in Table 3, an airport would spend $260,000 in O&M costs per deicing outfall to operate 

and maintain a plug and pump system that would achieve the 40% collection requirement. 

Table 3. Normalized Capital and Operating Costs for the Block-and-Pump Collection System 

Deicing 

Annual 

Operating and 

Normalized 

Annual 

Operating and 

 

1

 These O&M costs include permit monitoring, glycol management, the pumping contractor, plus other 

miscellaneous costs (ERG, May 3, 2007). 
Memorandum 

November 16, 2011 

Page 5 of 5 

Airport Outfalls Maintenance 

Cost (2006 $) 

Maintenance 

Cost (2006 $) 

Minneapolis 5 $1,300,000 $260,000 

 

Example Calculation 

The following example shows how the cost model estimated annualized plug and pump costs for the Port 

Columbus, Ohio airport based on the number of stormwater deicing outfalls reported in the questionnaire. 

See the Economic Analysis (DCN XXXX) for details on how capital costs were amortized. 

Number of ADF contaminated stormwater outfalls at Port Columbus: 7 

Calculated capital cost per outfall: $263,400 

Calculated O&M cost per outfall: $260,000 

Total capital cost = $263,400/outfall x 7 outfalls = $1,843,800 

Amortized plug and pump capital cost = $245,342/yr2

 

Annual Operating and Maintenance Cost for Port Columbus: $260,000/outfall x 7 outfalls = 

$1,820,000/yr 

Annual Cost for Port Columbus (annualized capital plus annual): = $245,342 + $1,820,000 = $2,065,342 

 

2

 See the final rule Economic Analysis for Effluent Limitation Guidelines and Standards for the Airport Deicing 

Category Document (AD01280) for a description of amortization of capital costs.