State lists polluted streams
| • | Hawai'i's impaired streams, 2002 |
By Jan TenBruggencate
Advertiser Science Writer
Every stream on O'ahu and one-third of streams statewide are polluted, according to the state's Environmental Planning Office.
Flowing fresh waters across Hawai'i are defiled with mud, fertilizer, pesticides and trash. The state's efforts to respond are so preliminary that many of the polluted streams have not even been assessed, and many of those have had only visual inspections.
The state has neither the money nor the staff to do full chemical analyses on all of Hawai'i's polluted streams, said June Harrigan, manager of the state's Environmental Planning Office. Even more distant is the hope of doing something significant about polluted streams.
"It has been very slow as far as getting anything in protecting our waters and our streams," said Kaipo Faris, spokesman for the Hihiwai Stream Restoration Coalition. But he said there are some hopeful signs.
The state, in compliance with the federal Clean Water Act, in 1998 listed 19 Hawai'i waters as polluted, three of them streams. The Hihiwai coalition in 2000 filed suit against the Environmental Protection Agency, arguing that the list was woefully inadequate. Federal District Judge David Ezra ordered the state to include other polluted waters, and the stream list increased twentyfold.
The new list released last year included 59 streams plus the Ala Wai Canal as impaired waters. The list also included dozens more dirty coastal areas, many of them fed by those polluted streams.
While the list includes 31 streams on O'ahu, Harrigan said her office believes every stream on O'ahu is polluted. Other islands have some near-pristine streams — most of them in remote areas, such as the valleys of Kaua'i's Na Pali and the rugged, undeveloped coasts of Maui and Hawai'i.
Faris said that while progress on identifying polluted streams, establishing what's polluting them, and eventually stopping the pollution is a long process, the lawsuit helped get the process moving.
"Finally, because of education and pounding on doors, it's starting to work. Interagency cooperation is starting to work, but a lot of funding and a lot of education are still needed," Faris said.
The Health Department, in its public comments on the stream report, said there are multiple threats to waterways: "In Hawai'i, streams, especially, have been historically degraded by habitat destruction, channelization, and polluted runoff of nutrients, sediments and toxic materials."
Most streams on the list are turbid, or muddy. Sediment can settle between rocks, changing the habitat for native stream fish. It can reduce light penetration, cutting off plant growth, and it can choke out stream life not adapted to muddy water.
Hawai'i's healthy streams have clear water, even after heavy rain. The power of the rainfall is broken by leaves and branches, and its flow to the streambed is filtered through humus, ferns and mosses. The water is often tea-colored from the tannin in fallen leaves but it is seldom muddy.
Urban streams, by contrast, are often muddy. And in those cases where laboratory analysis has been done, a frightening range of materials are found. Like the banned pesticides dieldrin and chlordane in Manoa and Nu'uanu streams, presumably leaching from homes treated for termites when these chemicals were common. Like enterococci bacteria, which can be indicators of pathogens associated with human or animal feces. And like the nutrients nitrogen, phosphorous and others, which may come from fertilizer or other sources.
The Department of Health expects to find more of these pollutants as it tests the state's streams.
"Regarding toxic substances, we have barely begun to test for these materials, but find them when these tests are run," the department said.
After identifying a steam as polluted, the next step is to establish what pollutes it and the source. This part of the work is called establishing the total maximum daily load, or TMDL — the amount of material that can enter a stream and have it still meet water quality standards. This process is being done for several high priority streams, but it is still years away for most polluted streams.
"Once they do the TMDL, we have a base, something we can go back to. It looks for diseases, heavy metals, sediment. It takes samples at different time — storm periods, dry periods — so you get an overall picture of the operation of that stream," Faris said.
"It is a pollution budget for the watershed, where we're able to identify existing loads and identify things needed to bring them back down," said Dave Penn, the Health Department's TMDL coordinator.
The final, and perhaps most difficult step, is to stop the inflow of pollutants, to find the source of the sediment, chemicals, fertilizer and other materials, and to persuade those responsible to stop them, he said. For that, substantially more money will be needed, he said. And since much of the pollution is from diverse sources, one of the keys is educating people.
"A lot of people think a stream is where you dump stuff," Faris said. "You look at the mouth of Kalihi Stream. There are batteries, tires, shopping carts. The water is slow and warm and full of introduced species. The best indicators of a good stream is that it's cool, and flowing and full of native species."
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