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Sewage from Recreational Activities

Minimum Measure: Illicit Discharge Detection and Elimination

Subcategory: Decentralized Wastewater

Photo Description:  Many marinas provide pump-out stations for safe disposal of bilge


Management measures regulate wastewater generated by outdoor activities by providing alternatives to illegal sewage discharges. Under federal law, it is illegal for boats to discharge marine sewage in navigable U.S. waters, including coastal waters up to three-miles offshore. The law also specifies that there be "no discharge" by boats operated on lakes and reservoirs or on rivers not capable of interstate navigation. Boats with installed toilets must have an operable Coast Guard approved marine sanitation device (MSD) that holds sewage for pump-out ashore, for discharge in the ocean beyond the three-mile limit, or that treats the sewage to federal standards prior to discharge.

Properly disposing of sewage generated by recreational activities avoids the effects these activities and their associated developments (i.e. marinas and campgrounds) can have on aquatic environments. Marina and recreational boat sewage can have substantial effects on water quality by introducing bacteria, nutrients, and hazardous chemicals into waterways. It has been reported that a single discharge of human waste can be detected in a one-square-mile area of shallow, enclosed water (FL DEP, no date). Human wastes can include Streptococci, fecal coliform, and other bacteria that contribute to incidences of human disease, shellfish bed closures, fish comsumption advisories, and algal blooms. Boats can be a significant source of fecal coliform bacteria in areas with high boating densities and low hydrologic flushing. Fecal coliform levels become elevated near boats during periods of high occupancy and usage (USEPA, 1993). Holding tanks on boats also concentrate pollutants and use increased levels of oxygen during decomposition. Table 1 shows a comparison of the biological oxygen demand required to decompose sewage held by MSD's versus untreated and treated municipal sewage (FL DEP, no date).

Table 1. BOD concentrations according to sewage type



BOD concentration

Boat Sewage

1,700 - 3,500 mg/l

Raw Municipal Sewage

110,400 mg/l

Treated Municipal Sewage

5,100 mg/l

Implementing proper disposal practices and providing services for removal of recreational wastes can alleviate the effects that this source of pollutants has on water quality.

Best management practices controlling recreational sewage sources are applied most often in coastal areas and freshwater waterbodies favored by recreational boaters. A marina's location, flushing times, and circulation patterns, among other physical factors, can affect sewage releases to surface waters. Additionally, inadequate maritime sanitation devices can also result in unintended sewage discharges. Climactic factors can also influence sewage discharges. Rain and wind affect sewage circulation and flushing times. Proper siting of marina basins and adequate planning for disposing of boat sewage are important considerations when addressing illicit maritime discharges. The same basic siting techniques and disposal provisions apply to sewage generated at campgrounds.


Several management practices can reduce the sewage discharges from vessels at marinas. These practices range from installation of pump-out systems to public education to inspection of marine sanitation devices. The use of the following practices is encouraged to help reduce the incidence of improper discharges from vessels:

  • Pump-out Installation and Operation. Pump-out stations are an efficient method to control sanitary discharges from boating activities. Pump-out facilities collect waste from on-board MSDs, which are recommended for vessels over 25 feet. EPA Region 1 determined that, in general, one pumpout facility per 300 toDash600 boats with holding tanks (type III MSDs) should be sufficient to meet the demand for pump-out services in most harbor areas (USEPA, 1991b). EPA Region 4 suggested one facility for every 200 to 250 boats with holding tanks (USEPA, 1985a). The State of Michigan has instituted a no-discharge policy and mandates one pump-out facility for every 100 boats with holding tanks (USEPA, 1993).

    There are three types of pump-out stations: a fixed collection system, a mobile/portable system, and a slipside system. All three systems remove sanitary wastes through a flexible hose connected to the wastewater fitting in the boat's hull. Wastewater is pumped or vacuumed to an onshore holding tank, sanitary sewer system, or approved disposal facility. However, there are differences in the cost, location, and use of each of the three collection systems. Fixed systems include one or more centrally located sewage pump-out stations. These stations are often located at the end of a pier, typically near fueling docks, so that fueling and pumpout operations are easily accessible. Portable/mobile collection systems are similar to fixed-point systems, but are capable of being moved around a marina to provide pumpout services at various locations. This collection system is connected to the vessel's deck fitting, and wastewater is pumped from the vessel's holding tank to the pumping unit's storage tank. The contents of the storage tank are then discharged into a municipal sewage system or a holding tank for removal by a septic tank pump-out service. Another form of portable pump-out is the radio-dispatched pump-out boat. The pump-out boat goes to a vessel in response to a radio-transmitted request, eliminating the inconvenience of mooring and maneuvering vessels in high-traffic areas. (USEPA, 1993). Slipside or remote systems provide direct hookup and continuous wastewater collection at a boat slip. EPA recommends that slipside pump-out be provided to live-aboard vessels (USEPA, 1993). Marina slips designed to serve transient boating populations can be served by either fixed or mobile pump-out systems.

    According to a 1989 American Red Cross Boating Survey, approximately 19 million recreational boats sailed in the waters of the United States (USCG, 1991). About 95 percent of them were less than 26 feet in length, and most lacked on-board marine sanitation devices. These boats often use only small portable (removable) toilets, requiring planning for sewage disposal. A satisfactory disposal facility for this type of device could be a dump-station, possibly located at the end of a pier. Given the large percentage of smaller boats, marinas that service significant numbers of these boats should provide portable toilet waste-disposal facilities(USEPA, 1993).

    Pump-out facilities should be open during times when customers are most likely to use their services. Weekend morning and evening service, when demand is high, will encourage the use of pump-out facilities. Pump-out fees should be kept at reasonable rates to encourage use. An EPA conducted willingness-to-pay survey found that boaters would accept a fee of between $3 and $7 for pump-out service (Sea Grant, 1992). Some marinas offer free pump-out services, financing the cost through slip fees or environmental surcharges. Pump-out facilities require routine inspection to ensure the proper functioning of equipment.

  • No-discharge area designations. No-discharge areas are zones where it is illegal to discharge sanitary waste (treated or untreated) from vessels. Once an area has adequate pumpout facilities, states can apply for this designation. The only type of marine sanitation device that can be legally used in these areas is Type III MSDs (holding tanks). The benefit of no-discharge areas is that they can significantly reduce the amount of bacterial contamination from illegal discharges of vessel waste. In Rhode Island, water quality studies indicate that levels of fecal coliform have declined during the boating season since the establishment of a no-discharge designation (RI Sea Grant, 1992)

  • Education. Pump-out facilities are of little use if boaters do not use them. Many boaters are unaware both of state and federal regulations requiring the use of marine sanitation devices and of the location of pump-out services. Like most forms of educational outreach, the use of pamphlets, newsletters, bill inserts, and meetings are often used to inform boaters of available pumpout services. Offering free inspections of customer MSDs through the Coast Guard Auxiliary Boating Safety Program is another way to control illegal wastewater discharges. Sources can be identified through public complaints, visual screening, water sampling from manholes, outfalls during dry weather, and use of infrared and thermal photography (USEPA, 2000a).

  • Enforcement. In some states, laws have been passed granting local harbormasters the authority to enforce MSD requirements and to fine violators. Ensuring that local and state laws are passed granting enforcement authority will allow for the inspection and identification of MSDs that are not operating properly.

    Dye tablets placed in holding tanks discourage illegal disposal. That's the finding of Avalon Harbor, California, which used the method to identify fecal coliform bacteria sources, but discovered it was also useful in reducing pollution levels. During the first three years of the practice, 135 violations of the no-discharge policy were detected. A harbor patrol officer boards vessels entering the harbor and places dye tablets in all sanitary devices. One tablet in approximately 60 gallons of water provides a visible dye concentration of one part per million. A supply of 200 tablets cost about $30 (Forestry Suppliers, 1992, as cited in USEPA, 1993).

  • Signage. Signs marking pump-out station locations and hours of operation should be placed in prominent places where marina tenants tend to gather. If the pump-out station serves an entire harbor, then signs should be placed in neighboring marinas and mooring areas to direct boaters to the station. Self-service pump-out stations need to include a sign that provides operating guidance. Pump-out signs may be available through either state or federal programs, and marina owners should be encouraged to place these signs near each pumpout station.


The management practices for controlling sewage generated by recreational activities are limited mostly by a lack of pumpout facilities and a lack of boater education programs that stress techniques to prevent wastewater discharges. These two factors have been called the most important in successfully preventing sewage discharge (USEPA, 1991b). The cost of pump-out facilities has also been cited as a limitation, but this may be due to a lack of awareness about federal and state grant programs to aid in pump-out station installation.

Maintenance Considerations

In general, marina pump-outs are fairly inexpensive to operate and maintain. Maintenance considerations can include scheduling of inspection and replacement of pump-out equipment, cleaning of hoses and pump-out connections, and hiring of a service to remove sewage not discharged into the sanitary sewer.


Limited data are available on the effectiveness of management practices to reduce water quality impacts from illegal wastewater discharges in marinas. The water quality effects of improper sewage discharges include elevated fecal coliform bacteria levels and reduced oxygen levels in the water. A single weekend boater flushing untreated sewage into our waters produces the same amount of bacterial pollution as 10,000 people whose sewage passes through a treatment plant (CA DBW).

Marine sanitation devices can also introduce harmful chemicals into the aquatic environment. Chemicals used to disinfect and deodorize the waste include formaldehyde, paraformaldehyde, quaternary ammonium chloride, and zinc sulfate. Some of these chemicals are known carcinogens and have adverse impacts on aquatic organisms.

Cost Considerations

Costs associated with pump-outs vary according to marina size and type of pumpout system. Table 2 presents EPA cost information for three marina sizes and two types of pumpout systems (USEPA, 1993). The average cost for pumpout installation has been estimated to be $5,323 (RI Sea Grant, 1992). Portable pumpout facilities are believed to be the most logistically feasible, convenient, accessible, and economically affordable way to ensure proper disposal of boat sewage (Natchez, 1991).

Depending on the type of pump-out system installed, maintenance costs can range between $36 and $200 per slip per year. Table 2 contains operation and maintenance figures for three types of sewage pump-out collection systems. As the table shows, operation and maintenance is more expensive for marina-wide and portable systems than for slipside systems. This extra expense is balanced by the lower capital cost for system installation, both for marina-wide and portable systems.

Table 2. Annual per slip pump-out costs for three collection systems (Source: USEPA 1985 as cited in USEPA, 1993)

Portable/Mobile System
Slipside System
Small Marina (200 slips)
Capital Cost
O&M Cost
Total Cost (slip/year)
Medium Marina(500 slips)
Capital Cost
O&M Cost
Total Cost (slip/year)
Large Marina(2,000 slips)
Capital Cost
O&M Cost
Total Cost (slip/year)
aBased on 12% interest, 15 years amortization
b12% interest, 15 years on piping, 12% interest, 15 years on portable units

The University of Rhode Island Sea Grant performed case studies of best management practices for stormwater pollution related to boating. The three case studies in Table 3 examined various public education techniques for their cost, educational value, and cost effectiveness. While these public education case studies did not focus exclusively on boat sewage practices, the results can be used as an indicator of expected cost and performance for recreational sewage BMPs.

Table 3. A review of three BMP case studies for marinas (Source: RI Sea Grant, 1992)



Educational Value

Cost Effectiveness

Conducting Workshops

Low cost ($16 per facility) but requires considerable investment of time

Ranked last among customer choices for receiving information
Low turnout
Only 31% of attendees have used BMP's

Low unless attendance is tied to a more popular marina event

Distributing Literature

$52.80 per marina for distribution through display rack ($45 for rack and $7.80 for copies)
$45.36 if done through monthly mailing

Ranked as the second most popular way of receiving information
75% reported reading fact sheets and 91% of these readers indicated that they began using practices learned

High if monthly mailing method is used

Posting Signs


Ranked first as the most popular way of receiving information

Very cost effective since signs can be used for several years.

Federal aid is available to states for the construction, renovation, operation, and maintenance of pump-out and dump stations to improve water quality. The Clean Vessel Act Grant Program also provides funds for educational programs on the environmentally safe disposal of human waste. The federal share of any project cannot exceed 75 percent of the total cost, and marina operators agree to the following conditions:

  • Pump-out facilities will be operated, maintained, and accessible to all recreation vessels for the full-period of their useful life
  • The national pump-out symbol shall be installed and must be clearly visible to boaters.
  • An informational sign shall be installed at pump-out stations and will specify fees, restrictions, hours of operation, operating instructions, and a contact name and telephone number to call if the facility is inoperable.

The maximum user fee that can be charged for pump-out use is $5. It may be charged for use of pumpout facilities constructed or maintained with grant funds. See the Clean Vessel Grants Program Exit EPA Site website for further information.


Florida Department of Environmental Protection. No Date. Clean Vessel Program: Frequently asked questions by boaters. Florida Department of Environmental Protection, Division of Law Enforcement, Tallahassee, FL.

Maryland Department of Natural Resources. 1990. A Guidebook for Marina Owners and Operators On the Installation and Operation of Sewage Pumpout Stations. MD DNR, Boating Administration, Annapolis, MD.

Maryland Department of Natural Resources. 1998. Maryland Clean Marina Guidebook. MD DNR, Waterway Resources Division, Annapolis, MD.

Natchez, D.S. 1991. Are Marinas Really Polluting? International Marina Institute, Wickford, RI.

Ohrel, R., R. Gonzalez, and G. Robbins. 1995. Don't Miss the Boat: Managing Marinas for Water Quality Protection. Center for Watershed Protection, Ellicott City, MD.

Oregon State Marine Board. No date. Boat Waste,What You Can Do. [ Exit EPA Site]. Accessed September 14, 2005.

Rhode Island Sea Grant. 1992. Environmental Guide for Marinas: Fact Sheets available on-line. University of Rhode Island Bay Campus, Narragansett, RI. [ Exit EPA Site].

USEPA. 1993. Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters. U.S. Environmental Protection Agency, Office of Water, Washington, DC.


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Last updated on July 10, 2012