When a citizen activist group threatened 10 Yakima Valley dairies with Clean Water Act suits last fall, Washington state's largest dairy region erupted. Farmers and activists lived in fear of each other. Politicians looked for solutions, and regulators tried to soothe tensions.

Underneath the bedlam was the real story: After a decade of phenomenal growth, the dairy industry dominated the communities on the lower half of the river. Any threat to the industry was a threat to a way of life and the relative prosperity of arid eastern Washington. Few even realized the Yakima Valley had quietly become the state's dairy capital. A quick check of the U.S. agricultural census showed that fact: The number of dairy cows in the area increased from 27,000 to 68,000 in eight years.

People in the industry knew why: Over the last 10 years, population pressures in western Washington and California forced dairy farmers to the dry, less populated stretches of eastern Washington. But they weren't taking care of the cow manure. The runny muck was routinely running into irrigation canals that drained to the river. It had been going on for two decades. The story was as emotional as they come. With the threat of lawsuits, few farmers would talk.

List service

The state Department of Ecology, however, had all the numbers to validate the Tri-City Herald's four-day series that ran in early March 1998. The agency had been gathering water quality data for several years. The Herald acquired two databases kept by the state to track water quality problems. The lists are mandated by the Clean Water Act and are known as 303(d) and 305(b) for their sections in the act. They show state waters that aren't up to federal standards and also tell what's wrong with the water.

As my first attempt at using Access, with lots of help from our CAR coordinator David Cuillier, I looked at the state data, zeroing in on water monitoring stations on the lower Yakima River. I found that several spots had more fecal coliform than 90 percent of the state's waters. That proved the poop problem.

We also isolated key water stations and determined the level and general cause of the pollution, which is largely agricultural. For a broad look at a state's waterways, the 305(b) list is a good start. It's an overall indicator of water quality and - at least in Washington - comes in a much easier format for database searches. Every monitored waterway is tested for a handful of pollutants, including temperature, dissolved oxygen, pH, and fecal coliform. That makes it easy to search for pollutants from a specific industry, such as dairy farms.

Standard usage

Obviously, however, even something as specific as coliform has a variety of sources, and those sources probably will be listed generally. The 305(b) list is handy because it shows whether a water segment is clean enough for specific uses, such as fish spawning, swimming or boating. That way, it's possible to search for all the places in an area where fish can't survive. Or where people shouldn't swim.

Pollutants in the 305(b) list are also given a rating that indicates the percent of tests in which they exceeded quality standards. That can be used to rank state waters by pollutant. Unfortunately, the sample size is sometimes rather small, so a stream that failed 100 percent of the time may only have been tested two or three times in the last 10 years.

That's where the 303(d) list comes in. It is more specific and details tests.

States use the test data to create Total Maximum Daily Load studies that target specific pollution problems and cleanup measures. The only such study completed in Washington is on the Yakima River. It focuses on the long-lived pesticide DDT and sediment, which were both included in the Herald's package.

Washington has had trouble producing enough of those studies to please Northwest environmentalists. The state is now on a 15-year schedule under threat of lawsuit. The 303(d) list is great for looking at specific water sections and finding out who did the tests.

For all the hours spent searching the databases, the amount of data-crunching results that made it into the final stories was minimal. It was too abstract and technical for the average reader. But knowing how an agency keeps records helped us ask better questions. And having the data allowed us to say the Yakima River was - at least by some parameters - the dirtiest waterway in the state of Washington.

Mike Lee can be reached by email at mlee@tri-cityherald.com