Vessel Discharge
of Sewage
Pumpout Installation
Summary
If you have vessels within your facility that have on-board marine sanitation devices, consider installing a pumpout facility. EPA Region I assumes that vessels over 25 feet have an on-board marine sanitation device (EPA, 1991).
Although not every marina facility is required to have a pumpout station, each facility that stores boats greater the 25 feet in length is encouraged to install one because pumpout stations, when used, are the most efficient means for removing sanitary waste from boats. Pumpout stations can also attract customers who want to keep their boats moored or docked in areas where they can easily pump out their holding tanks.
The location of pumpout stations in Rhode Island is based on the size of the boating fleet in a particular harbor. EPA Region I has identified two types of harbors, transient (destination) and nontransient. For harbors that are deemed transient, one pumpout is required for every 300 boats over 25 feet or with an installed MSD. If information about boat size is unavailable, the state counts all boats in the harbor. Nontransient harbors that serve as boat parking lots require one pumpout per 600 boats. In order for a pumpout to be included in the count, it must be a fixed unit, tied directly to a sewer line or holding tank. A mobile pumpout station (vessel or cart) can be used in the count, if it is working in coordination with an approved fixed system in the particular cove or harbor. The purpose of this requirement is to ensure that there is a continuous means of holding and disposing of the waste once it is collected. Without this requirement, it is more difficult to monitor the final fate of the boat sewage once it is collected. This also guards transfer of waste from the harbor where it was collected to an unsuspecting sewage treatment plant in another geographic region.
The permit process for installing a pumpout is managed by the Coastal Resources Management Council (CRMC) and the state Department of Environmental Management (RI DEM). General requirements of the permit usually include:
- Assent from CRMC to permit construction in a coastal zone
- Order of approval from the local sewer treatment plant if you are tying directly into a sewer line
- Order of approval from the Division of Water Resources at RI DEM for a sewer connection if a holding tank needs to be installed
Pumpout stations are manufactured by numerous companies. Each type of pump has individual characteristics that need to be considered in evaluation of the specific site. The basic criteria used in pump selection are the pump's capacity and the distance, both in height and length, it can move waste through a pipe. Other considerations may include durability and ease of operation and maintenance. A pumpout system includes four functional parts: flexible hose and nozzle; pump machinery; pipe lines; and sewage disposal system (Ross and Amaral, 1992). Pump types include centrifugal, diaphragm and vacuum designs.
Centrifugal-Moves sewage by using an impeller that pushes the waste to the outside of the impeller by using centrifugal force. This forces the sewage to flow through the impeller as it rotates.
Diaphragm-Moves sewage by lifting up and pushing down a diaphragm in a pump casing. The upward motion sucks sewage into the pump casing through a check valve. During the downward motion, sewage is pushed out of the pump casing through the outlet check valve.
Both of the above systems have parts that are in direct contact with the sewage, and the centrifugal pump requires priming.
Vacuum-Moves sewage by creating a vacuum between the hose nozzle and an accumulator tank. When the accumulator pump is full, the vacuum is reversed, sending pressurized air into the tank and pushing the sewage out to the disposal system.
In addition to the type of pump utilized, consider where to locate the pumpout station and how to dispose of the waste once it is collected. Pumpout stations can either be fixed, mobile, or remote-operated. Mobile pumpouts can be attached to a pumpout vessel and used in the harbor area or attached to a cart and used within the marina. Both methods allow the pumpout to get to the customer easily. Mobile pumpout boats have worked particularly well in areas with a high number of boats on moorings, such as Great Salt Pond on Block Island, Rhode Island. Fixed stations are permanently mounted in a location within the marina that is accessible to boaters, generally on an existing gas dock. Remote stations provide a direct hookup to multiple locations or each slip within a facility. These systems are expensive but provide the most convenient means for customers to pump out their holding tanks. Fixed and remote stations must be directly attached to either a sewer line or a holding tank.
The cost to install a pumpout system ranges greatly, depending on the type and location within the facility. According to a 1992 EPA report, the average cost to install a pumpout facility is $5,323 and can range in cost from zero to $50,000 (Ross and Amaral, 1992). Total costs include engineering and permit fees, pumpout machinery and pipes, excavation and installation charges. A helpful guide on the installation and operation of pumpout stations has been completed by the Maryland Department of Natural Resources, Boating Administration. The guidebook provides a partial list of portable, stationary, and remote pumpout units available according to manufacturer's model. A copy of A Guidebook for Marina Owners and Operators On the Installation and Operation of Sewage Pumpout Stations can be obtained by writing the following address:
Maryland Department of Natural Resources
Boating Administration
902 Commerce Road
Annapolis, MD, 21401An abridged listing of pumpout manufacturers is located in Appendix C of the hard copy of this document.