Both maintaining a properly functioning sewage system and using best practices in sewage handling are the first steps in reducing human health risks and protecting the environment. Raw or poorly treated sewage is harmful to human health and water quality. Typhoid, hepatitis, cholera, gastroenteritis and other waterborne diseases may be passed directly to people who swim in contaminated waters. Simply stated, odors and poor water quality within the marina basin are not good for business.
Sewage degrades water quality in several ways. Because the microorganisms within sewage need oxygen, any waste — also called effluent — discharged to waterways reduces the amount of oxygen available to fish and other forms of aquatic life. Furthermore, the heavy nutrient load in sewage promotes excessive algal growth. As the algae multiply, they prevent life-giving sunlight from reaching vegetation below the surface. When the algae die, bacteria that decompose the dead matter use oxygen, further reducing levels of dissolved oxygen available to other organisms.
This Unit addresses a variety of sewage handling considerations for marina operators. If you are unfamiliar with the three U.S. Coast Guard-approved types of marine sanitation devices, Section 2: Services and Education offers an in-depth explanation of the devices. You may want to become familiar with the options before working through this Unit.
Best Management Practices and Legal Setting
This Unit includes two sections of best management practices, an overview of the legal setting, and a Unit Review. Best management practices cover sewage handling infrastructure and services and education. The following list provides an outline of BMPs you will find within each section.
- Prohibit the discharge of sewage
- Install a pump-out system
- Provide restrooms on shore
- Maintain septic systems
- Provide facilities for “live-aboards”
- Understand marine sanitation device (MSD) requirements
- Offer MSD inspections
- Encourage MSD compliance
- Handle graywater properly
- Educate boaters
Before reviewing the best management practices, please take a few moments to review the legal setting for sewage handling at marinas. This overview of federal laws and regulations aims to provide a framework for shared requirements. However, it is a starting point and not a complete reference; please consult your state officials for complete requirements. Also, see: State Laws page for your state.
Federal Water Pollution Control Act (Clean Water Act), Section 312
The Clean Water Act (33 USC 1322) – Section 312(a) – (m), provides the legal framework under which U.S. Environmental Protection Agency and the U.S. Coast Guard regulate sewage releases from vessels. The discharge of untreated sewage from a vessel is not permitted in the Great Lakes or any inland body of water. If a vessel has a toilet or head installed, it must be equipped with an operable marine sanitation device (MSD). See: Vessel Sewage Discharges and No Discharge Zones (USEPA).
Marine Sanitation Devices
For purposes of the Clean Water Act (CWA), a marine sanitation device is defined as “any equipment for installation on board a vessel which is designed to receive, retain, treat, or discharge sewage, and any process to treat such sewage“ (33 USC 1322(a)(5)).
Section 312 of the CWA(h)(4) requires the use of operable, U.S. Coast Guard-certified marine sanitation device (MSD; Type I, Type II, or Type III) onboard vessels that are:
- Equipped with installed toilets, and
- Operating on U.S. navigable waters (which include the three mile territorial seas).
The MSD requirements do not apply to vessels that do not have installed toilets (e.g., vessels with porta-potties); however boaters using portable toilets are subject to the same regulations that prohibit the disposal of sewage into the Great Lakes. Most pump-out facilities have wand attachments to empty portable toilets, and some marinas have portable toilet dump stations.
Implementing regulations for the statutory requirements laid out by the Clean Water Act are found in the Code of Federal Regulations:
- EPA regulations implementing CWA section 312 (standards for marine sanitation devices (MSDs)): 40 CFR 140 et seq.
- U.S. Coast Guard regulations implementing CWA section 312 (regulations governing the design, construction, certification, installation, and operation of MSDs): 33 CFR 159, Subparts A-D.
No Discharge Zones
Under section 312(f) of the CWA, areas can be established where sewage discharges from vessels are not allowed. These areas are known as “no discharge zones” — zones in which both treated and untreated sewage discharges from vessels are prohibited. Within no discharge zone (NDZ) boundaries, vessel operators are required to retain their sewage discharges onboard for disposal onshore at a pump-out facility. (Note: for ocean-going vessels, sewage can be stored for release at sea, beyond three miles from shore.) When operating a vessel in a NDZ, sewage treatment systems must be secured to prevent discharge. Since NDZ waters have greater environmental protection, even vessels with Type I or II marine sanitation devices are prohibited from discharging treated sewage into these areas, and they must be properly secured to ensure that sewage discharge will be prevented. (Check with your state for how to secure the Type I or Type II system; see the State Laws page for your state.)
All freshwater lakes, reservoirs, and rivers not capable of interstate vessel travel are defined by the Clean Water Act as NDZs. States may establish an NDZ in other state waters with the approval of the U.S. Environmental Protection Agency (40 CFR 140.4). U.S. Coast Guard and the state in which the NDZ has been designated may enforce the NDZ requirements (33 USC 1322(k)).
Clean Vessel Act (CVA) Grant Program
The Clean Vessel Act Grant program (50 CFR 85) provides grant funds for the construction, renovation, operation, and maintenance of pump-out stations and waste reception facilities for recreational boaters and also for educational programs that inform boaters of the importance of proper disposal of their sewage.
The governmental agency designated by each respective governor is eligible to participate in the CVA program. The governmental agency may partner with local governments, private marinas and others to fund eligible projects. Grant funds are made available through a nationally competitive process. The ranking criteria, eligible projects and regulations are listed in 50 CFR 85 and outlined in “Install a Pump-out System” found in Classroom Unit 6, Section 1: Sewage Handling Infrastructure.