Raritan Engineering Holding Tanks & Waste Treatment Systems

Raritan Engineering: A Pioneer in Marine Waste Treatment

When it comes to keeping our waterways clean, few names carry more authority than Raritan Engineering. Since 1958, Raritan Engineering Company has been at the forefront of marine sanitation innovation. That legacy is on full display in their Holding Tanks & Waste Treatment Systems lineup — a category where Raritan has not only met regulatory standards, but consistently exceeded them for decades.

From Holding Tanks to Active Treatment

Understanding the difference between passive holding and active waste treatment is central to choosing the right onboard sanitation setup. Any boat with an installed marine toilet must have either a Type I MSD, which treats waste and makes it safe for overboard discharge; a Type II MSD used for the same purpose but treating to a higher standard typically designed for vessels over 65 feet; or a holding tank Type III MSD. Raritan offers solutions across this spectrum, giving boaters the flexibility to choose what works best for their cruising environment.

Raritan believes that treating a single flush at the source and discharging into tidal water is far more effective than risking having a holding tank dumped overboard when a pump-out cannot be found or is not functioning. At the same time, they recognize that each user has unique needs when boating — for many, a holding tank may be the best solution, while some prefer to treat and discharge.

The Electroscan: Chemical-Free Treatment Technology

The Raritan Electroscan is the gold standard in Type I Marine Sanitation Devices, offering EPA- and USCG-certified onboard sewage treatment for vessels under 65 feet. Waste is macerated and processed using Raritan's patented electrode technology, which generates hypochlorous acid from natural seawater — a powerful disinfectant that kills bacteria and viruses on contact, with no chlorine additives or harsh chemicals required. After treatment, the treated wastewater returns to its original state of salt and water, so no harmful chemicals enter the environment.

The performance numbers are striking. Independent tests consistently show the Electroscan treats effluent to well below the EPA limit of 1,000 coliform/100 mL — often achieving readings under 14 coliform/100 mL. The system also features simple one-touch toilet flushing and treatment activation, recording each treatment cycle, with key info displayed on an easy-to-read LCD display — and solid-state overload protection eliminates fuses and relays.

The Purasan EX: Freshwater-Friendly Treatment

For boaters navigating freshwater lakes and rivers where saltwater-dependent electrochemical systems aren't practical, Raritan offers the Purasan EX. The Purasan EX is a flow-through system in which the toilet is connected to the tank and the tank is connected to the thru-hull — with each flush, waste enters the tank where a small amount of disinfectant is introduced to neutralize the waste, and an equal amount of treated waste is forced out overboard. The Purasan EX utilizes the same chemical used in many municipal treatment plants.

Odor Control: The K.O. System

For boaters who rely on traditional holding tanks, Raritan's expertise extends to keeping those systems odor-free. A bio-active (live aerobic bacteria) holding tank treatment such as Raritan's own "K.O." works with the aerobic bacteria in sewage, eliminating odor, completely emulsifying solids and paper, and preventing sludge from forming. It's a science-driven approach rooted in the same principles used in composting and sewage treatment facilities on land.

Why Raritan Stands Apart

Raritan Engineering Company Inc. is a family-operated enterprise specializing in marine sanitation devices, holding reservoirs, and other sanitation attachments, with over 65 years in operation establishing itself as a foremost manufacturer of marine sanitation products. Raritan offers a standard 2-year warranty covering parts and labor, with options to extend coverage up to 5 years through their Guardian Support Services. For boaters who want reliable, environmentally responsible waste management backed by decades of engineering expertise, Raritan's holding tanks and waste treatment systems represent a trusted standard on the water.