By Jan TenBruggencate
Advertiser Columnist

Many storm drains in the Islands have been painted with lettering indicating that anything washing down them goes directly to the ocean.

The idea is to keep people from dumping chemicals and other bad stuff down the storm drains.

But in rainy periods, a lot of debris, oil residue from roads and parking lots, and other materials wash into the drains regardless. Just look at the debris that collects along any roadside.

In parts of the Mainland — notably California — storm drains, by law, must be fitted with catchment devices to trap debris. Several firms are producing equipment that can do so in Hawai'i as well.

These entrapment devices generally have two functions: They have nets or baskets to catch hard items such as bottles, branches, bolts and so on, and they have pouches that can trap oil residue, preventing it from reaching the sea.

Ameron Hawai'i markets one such system, the Fossil Filter FloGard system. Another system built by AbTech Industries goes by the name Smart Sponge.

There are others, including Stormwater Management's StormFilter and the Mycelx Stormwater Treatment System.

Fossil Filter representative Denny Moore said units are made to fit most any size drain, from the narrow inlets along curbs to rectangular or round drain openings.

Moore said his firm's units have already been installed at several locations on O'ahu, including the Filipino Community Center in Waipahu, the Pearl Harbor Commissary and locations in Salt Lake. They are to be installed at the Kahala Nui Senior Living Project.

The systems, which must be inspected and emptied every few months, are built so that extreme flows are not prevented from getting into the storm drains.

AbTech's Web site says it expects 95 percent of cities during the next three years to require systems that cut pollution in stormwater.

AbTech's Smart Sponge, like the Fossil Filter Fossil Rock pillow sold by Ameron Hawai'i, lies at the top of the drain, attracting petroleum products while allowing water to flow past.

AbTech says the system "permanently encapsulates oil, rejects water, is easy to install and is fully recyclable."

Fossil Filter's literature says that it installed 150 filters in the Dana Point, Calif. After three months, they had collected more than a ton of dirt and debris, plus large amounts of oil and grease that were trapped in the filters.

All of that stuff would have flowed into the nearshore waters if it had not been stopped.

Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. Reach him at (808) 245-3074 or jant@honoluluadvertiser.com.