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On the Marsh
HAYWARD MANEUVERS
Curbing flows through a 145-acre wastewater treatment marsh may have temporarily exacerbated rather than reduced ammonia in the Hayward wetland. Managers had hoped to reduce levels of this potential fish toxin by lowering effluent flows through the marsh from 10 to a maximum of 5 million gallons per day and by making a complementary series of physical and biological improvements. These steps were all aimed at fueling the growth of a bacteria that transforms the ammonia into a harmless nitrate. Since chlorine, another effluent constituent, kills this desirable bacteria, the improvements attacked the ammonia problem via the chlorine.
Since summer 1993, marsh managers have built a series of permanent baffles that promote chlorine evaporation by forcing the water through a maze of concrete piers and redwood slabs. The redwood, in turn, offers sound substrate for bacterial growth, backed up by 3500 clumps of additional hosts in the form of bulrush recently planted in bands crisscrossing the marsh.
While managers waited this year for the bulrush to mature (bands will be expanded with new plantings soon) and for two new dechlorination tanks to go in (installation is slated for this coming January), the lower flow levels had an unexpected side effect. The water hung around in the marsh longer, promoting localized algae blooms that changed the pH in the marsh and thus converted more ammonia from its nontoxic to toxic form. Another problem cropped up with the arrival of migratory waterfowl and an outbreak of avian cholera. Managers had to increase flows to dilute and flush out the bird-killing microbes. The higher flows, in turn, submerged and killed some of young bulrush plantings.
"It's going to be a balancing act, no matter what we do," says Rich Cortes of the Union Sanitary District, a partner in the ammonia control project with the East Bay Regional Park District, which owns the property. "A natural marsh isn't like a manmade treatment plant. It's dynamic. All we can do is respond," he says.
Finding a sound medium will be the focus of experiments to be conducted once the dechlorination tanks are in place. "We'll be looking for the ideal water height and flow rate to maximize plant growth and minimize ammonia," says Mark Taylor of the Park District. Despite the difficulties, Taylor says there's been one obvious benefit. Egrets and black-crowned night herons arrived last year to nest in the new bulrush - birds that usually prefer more arboreal nesting turf. Taylor counted over 115 egrets in the marsh this November.
Contact: Rich Cortes (510)790-0100 ext. 228 6/93
DEAL OR STEAL ON MAYHEWS?
In the 1950s, Margaret Lewis captured frogs in the brackish ponds of Newark's Mayhews Landing and chased snakes on its rolling grasslands. In the 1980s, she fought the efforts of developer Ed De Silva to put a housing tract on the grasslands portion. Today, she and 40 local environmental groups have objected to a price tag of $175,000 per acre for the grasslands and $5,000 per acre for the wetlands.
U.S. Fish & Wildlife agreed on July 1 to pay $7.5 million to add 108 acres of Mayhews Landing grasslands and wetlands to the S.F. Bay National Wildlife Refuge. Lewis says this price would set a precedent in the valuation of wetlands all over the Bay Area and propel them out of the economic reach of conservation groups.
Fish and Wildlife's John Doebel says the Interior Department Inspector General will commence an investigation of the Mayhews purchase this December at the request of Hayward Congressman Pete Stark, whom the environmentalists contacted with their concerns. In 1992, the Inspector reported that government was often overcharged for wildlands, despite use of certified appraisers and correct procedures. But Doebel doesn't expect the Inspector to find anything wrong with the Mayhews deal.
"Real estate in the Bay Area is too expensive," he says. "That is just a reality of doing business here."
Florence La Riviere, whose Citizens Committee to Complete the Refuge is credited with gaining 1988 legislation to double the size of refuge holdings around San Francisco Bay, says their once sound working relationship with Fish & Wildlife is now "severely threatened." She questioned the agency's appraisal history and process.
"Not only was the original appraisal unrealistically high to start with, but for them to declare no change since 1991 in the face of local land value depressed by 10, 20 and 30% since then, simply surpasses all credibility," says La Riviere.
Doebel says three 1990 appraisals were updated and that Fish & Wildlife procedures have been followed at all times. He says the high price stems from the fact that more than half the property is developable grasslands and uplands.
Requiring buyers like the federal government to pay closer to full-market value for lands like Mayhews where wetland regulations have derailed development may get a boost from the new Republican Congress. In the meantime, the Inspector General is set to publish new guidelines for Interior Department purchases this December.
Contact: Florence La Riviere (415)493-5540
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