By Mike A'Dair
November 19, 1999
"It's a pretty innocuous discharge, "said John Hannum, senior water resource control engineer for the North Coast Regional Water Quality Control Board out of Santa Rosa.
Hannum was characterizing the leachate that escaped from the grounds of the Mendocino Forest Products Company mill, about three miles north of Willits during heavy rains last week.
Hannum said that the results of water tests conducted Oct. 28 had been analyzed and revealed that the quality of the discharge was "not a big bells and whistles issue."
Test results indicated that the water had an electrical conductivity of 600 micromhos; suspended solids of 19 milligrams per liter, a salinity of 300 parts per million, and a pH of 6.
For comparison, the conductivity of drinking water is 200-500. Sewage has a conductivity of 5000-10,000 micromhos, Hannum told the Willits News.
Hannum added that the pH of 6 was too acidic and was probably the element in the range of data that was cause for the most concern. "
"Our water is supposed to be between 6.5 and 9," Hannum said. "Rainwater generally falls at a pH of 5.8 but after it runs off and percolates through the soil it picks up more alkalines, and we usually find it in streams and run off at a pH of 7.4 or 7.8, " Hannum said.
"(The MRC leachate) was not as acidic as acid rain. It's not even as acidic as rainwater. I know that the Willits Environmental Center wants to make a big deal out of it, but he facts aren't there to support that. This is just what happens when it rains on a tan oak mill, " Hannum said.
"That's some pretty good water, " Hannum said, characterizing the discharge from the Willits mill.
Hannum explained why the tannin released from a single mill could be much more intense than the tannin released naturally from all the tan oaks growing in the region's forests.
"Tannins and lignins are the glues that hold wood together," Hannum said. "The cell walls of plant cells are cellulose; the guts of cells are mostly water. The cell walls of the different cells in wood don't stick to each other, so the plant makes lignins and tannins to hold the wood together.
"With tan oak, the wood cells don't leak out the color until you break them up.
That's what the old tan oak mills did. There used to be wagon loads and train loads of tan oak bark taken to the tan oak mills to make tanning liquors for the tanning industry, " Hannum said.
Scott Harris, a Willits-based fisheries biologist with the Department of Fish and Game, agreed that the MRC discharge was innocuous.
"Well, first of all, that water was not entering a creek. It was flowing out into a wetlands area, sort of a bog, really, not directly into Outlet Creek," Harris said.
Harris said that this buffered the already mile effect of the tannin-laced water. "I certainly feel better about that water because of that," Harris said. "That whole bog was just as colored from natural tannins, as the water coming down from the mill," Harris said. "I really don't see any problem with it."
Harris said that the tannins can enter watercourses naturally. "Tannins occur naturally," he said. "It totally depends on the type of vegetation that is around. But, for example, alder is a type of tree that grows along watercourses and alders have tannins in their leaves. Certain watersheds, say, in the fall, that water is so dark from tannins that it looks black," Harris said.
Contrary to statements made last week by MRC president Sandy Dean and the Willits Environmental Center's David Drell, MRC has a permit to release industrial discharge.
According to Hannum, MRC filed a national pollutant discharge elimination system (NPDES) permit in July 1998.
The terms of the permit provide that MRC will stop any non-storm water discharge, will not discolor local streams, and will not harm the environment. Hannum said that Mendocino Forest Products Company is in non-compliance with its NPDES permit, and as such, the water quality board Nov. 12 sent a letter to MRC-MFPC, requiring it to self-monitor and report on water quality and leachate discharges after each storm event.
"This is a formalization of the process they are already obliged to do under their general (NPDES) permit," Hannum said.--TWN