Any oil in the bilge puts you at risk for an overboard discharge. Petroleum products discharged from the bilge are no different than spills at the fuel dock. Any spill that creates a sheen on the water can bring hefty fines. Here are some tips to prevent petroleum products from mixing with bilge water:
- Keep your engine tuned to minimize oil leaks.
- Check that clamps and filters are sealed properly.
- Inspect hoses and belts for peeling or cracking.
- When replacing hoses ensure they are the correct length, hoses that are too long or stretch to fit are prone to kink or collapse.
- Place an oil-absorbent pad under your engine and an absorbent bilge sock next to (but not interfering with) your bilge pump.
- Wipe up spills, drips and splatters immediately.
- There are many oil-only absorbent products on the market that can help make bilge maintenance easier. Some are oil-only absorbents that absorb oil and leave the water behind, others contain microbes that “eat” the oil over several days or weeks making disposal easier.
- Another alternative in dealing with dirty bilge water is an inline bilge filter. This device is designed to remove petroleum products from your bilge water without restricting bilge pump performance, allowing for a clean discharge. You must periodically check these products for oil saturation and replace filters as needed.
- If absorbent pads and filters haven’t done the trick, a few marinas now offer a bilge pump-out service. It’s still a new concept, so check with your local marine facilities for pricing and availability.
- Bilge cleaners can be a tempting solution to an oily bilge, while they can seem effective, many of these cleaners just suspend the oil in the soap and then both are discharged. If you use bilge cleaners try using a small amount on a cloth and use a hand bilge pump to remove to a bucket and dispose ashore.
A Note About Bioremediation
Absorbent products such as booms and socks that contain microbes or claim to "eat oil" may be used in the bilge of a boat. It is not legal for boaters to use loose or contained bioremediation products on a spill in open water. Only a trained spill response professional can legally apply these products to an open water spill.
For bioremediation products to work in your bilge they require the presence of a small amount of water, air temperature above 40 degrees and several days or weeks to be effective. In theory, after given enough time, the microbes will consume all of the oil or fuel, leaving behind clean water. Bioremediating products make disposal easier but do require time some as long as weeks to months to get rid of the oil.