This May, as we celebrate the anniversary of the birth of Rachel Carson -- the author of "Silent Spring, " which first inspired public responsiveness to the dangers of synthetic toxins -- we are stirred to consider progress that has been made in mitigating these threats to the human environment in our own backyard.

Mandates for cleanup of polluted soils at sites like the Badger Army Ammunition Plant routinely require that residual soil contaminants like lead do not pose excessive risks to humans. Based on recommendations from the Wisconsin Division of Public Health, maximum thresholds are established and are, for the most part, being enforced.

When achieved, this is the point where a "job well done " is proclaimed and responsible parties are freed from any further action. In practice, however, this means a "closed " site may still contain contaminant levels that are toxic to soil microbes, earthworms, plant species, grazing animals, grassland birds, etc.

Enforcement of our environmental regulations reflects a policy of measuring the severity of pollution or the success of cleanup by calculating the comparative risks to human health.

This effectively reduces the wide circle of species on the Wisconsin landscape to one -- the "ultimate " measuring stick for marking the acceptable threshold of environmental toxins on the land. But is this standard of measure in our best interest?

By devaluing the survival of even the smallest of species, we inevitably sanction compromise of our own viability.

Rachel Carson wrote: "Life not only formed the soil, but other living things of incredible abundance and diversity now exist within it; if this were not so the soil would be a dead and sterile thing. By their presence and by their activities the myriad of organisms of the soil make it capable of supporting the earth 's green mantle. "

This interdependence is reflected in Wisconsin administrative code, which explicitly requires consideration of risks to "terrestrial ecosystems " and taking the multitude of non-human species into account.

Such consideration, however, is only afforded when the additional cost to protect non-human species is negligible.

Of this, Wisconsin Department of Natural Resources ' south central regional director recently wrote: "For most cases closed by the (remediation and redevelopment) program, we do not consider the threats of environmental toxins to be significant enough to terrestrial ecosystems to justify the additional costs to remediate those threats. "

As a result, day by day contaminated sites are recorded and catalogued and mapped in massive databases.

The burgeoning inventory of closed contaminated sites is already in the thousands -- an unseemly reflection of what is valued and what is not.

It is time to recognize that the success of the species that we care about most is inextricably dependent on the state 's willingness to raise the bar to encompass species other than our own and the ecosystems that support them. It will require such an investment to tip the balance in our favor.

Olah, of Merrimac, is executive director of Citizens for Safe Water Around Badger; www.cswab.org.