Crucial Sludge Management Tips

The commercial maritime industry is comprised of many components, each requiring complex operational and logistical considerations. Aboard seagoing vessels, operation of machinery and equipment is made even more complex by the production of bilge wastes and sludge. Managing these vessel by-products is crucial, as failure to contain and control wastes can result in environmental disasters. Commercial marine insurance companies may offer pollution liability coverage as part of the policy, but vessel owners and operators must manage pollution risks with a careful understanding of sludge management. The following guide provides industry best practices for sludge and bilge waste management, protecting commercial maritime businesses and the environments in which they operate.

Sludge Aboard Seagoing Vessels: Common Sources

Aboard commercial marine vessels like cargo ships, tankers, and bulk haulers, numerous machines run 24 hours a day to provide propulsion and power for these vessels. Large engines are only part of the machinery puzzle; there may be electrical generators, auxiliary motors, and lifting equipment on decks. Each of these types of machinery produces sludge, a mixture of oil, water, and impurities. Common sludge sources include:

• Fuel oil purifiers/filters – as fuel oils are directed to engines for burning, they first pass through a filtration or purifier system. Sludge is separated and directed into holding tanks or specialized sludge tanks.
• Lubrication oil purifiers – machinery depends on lubrication for optimum performance. Just like fuel oils, lubrication oils are purified before use, passing through a filtration system. Any impurities are collected and stored in sludge tanks.
• Stuffing boxes and drainage trays – oil residues that burned during engine operation are scraped away and directed to stuffing box drains and eventually to sludge tanks. Drainage trays positioned under machinery capture leakage, and these also drain into sludge storage tanks.
• Waste oil tanks – sludge tanks are not the only storage locations for oily byproducts. Any oil residues produced by machinery are collected and stored in waste oil tanks. Waste oil tanks may also be used to temporarily store sludge until incineration.

Bilge wastes also bear discussion, as they are also mixtures of oil, water, and impurities produced by wave or weather activity on decks and in machinery rooms. Leaks of fresh- and sea-water pumps may also result in bilge waste accumulation. Bilge wastes are separated from an oil/water separator before the water component is discharged overboard; the oily residues are collected and stored in tanks.

Managing Sludge and Bilge Wastes

Based on the numerous sources of sludge aboard commercial marine vessels, it is easy to see that managing these oily wastes is no easy task. A complex network of filters, drains, pipes, pumps, and holding tanks must be employed to manage the collection and storage of sludge. Failure at any point within these complex networks can result in an overboard discharge, potentially causing severe harm to the environment. While commercial marine insurance packages typically offer some form of liability coverage for pollution spills, vessel owners need to minimize or eliminate any potential spill risks before they can cause damage.

First, vessel owners and operators must ensure all machinery and equipment is working properly. Inspecting tanks and discharge lines for leaks should be done on a routine basis, and corrections made before leaks can cause pollution discharges.

Next, proper discharge or incineration of wastes must occur. Incineration of sludge is done in specialized incinerators, found on board or onshore in cargo port facilities. Water is evaporated prior to sludge incineration. Carefully following preparation and incineration guidelines can reduce the chances of an environmental discharge or some other pollution spill.

Finally, training all stakeholders in the proper inspection, handling, and elimination of sludge and bilge wastes provides a powerful risk management aspect, supplementing the coverage afforded by commercial marine package insurance. Safety and sludge management training should form the basis of a safety-oriented shipboard culture, protecting employees and the environment alike.

About Merrimac Marine Insurance

At Merrimac Marine, we are dedicated to providing insurance for the marine industry to protect your clients’ business and assets. For more information about our products and programs, contact our specialists today at (800) 681-1998.