Working Waterfront

Lab Manager

Scott Bodensteiner

I was a biology major and a lot of my professors spent a lot of time talking about environmental issues. I went to work for an environmental group in Sacramento, the Sacramento Valley Toxics Campaign. that tried to raise money to help combat some of these problems. Now I work for MEC Analytical Systems in Tiburon.

Any water or sediment has to meet certain quality standards before it can be placed into the bay, to minimize ecological harm. The Clean Water Act incorporates a number of chemistry standards that dischargers have to abide by.

One of the big problems I foresee is the dredging industry cornering the regulatory community into placing black and white standards on sediment quality criteria as there are for water. There are no set-in-stone standards that sediment has to pass before it can be dumped, and that is what the dredging community wants to see happen. There are two different camps in the sediment testing community. One says that if certain chemistry tests are conducted then you can, without any doubt, without any further toxicity testing, tell whether sediment is contaminated to a degree that would prevent it from being dumped. However, the other camp says no chemical test can tell one hundred percent. They say you can’t draw a line like has been drawn with water standards, and that toxicity tests will always need to be done to confirm the quality of the dredged material.

The EPA has selected a number of standard species, based on availability and the ability of toxicologists to detect change over a short period of time so that a discharger can know within a week or so whether their wastewater is toxic. The toxicity testing guidelines for sediment usually include at least five different tests that involve not only different species but different environments. There’s concern about toxicity to the fish living in the water column that the sediment passes through after dumping, as well as for the community at the bottom of the bay where the sediment is going to settle.

Fortunately, the bay is relatively well flushed out because of the input from the rivers. But, on the other hand, there are chemicals being introduced to the rivers upstream that dump into the bay. And there are contaminants that have settled into the sediment and will be there for a long time. A number of these contaminants bind onto the sediment and then become re-suspended in the water if agitated, so that whatever is living in the water at that time is re-exposed. One of the big contaminants in the bay is mercury. Back in the Gold Rush days, mercury was mined around the Bay Area. It was used to extract gold from the ore they were mining up in the hills. Back then nobody had any idea that it was such a toxic compound, and the waste byproducts from these mercury extractions ended up in the rivers. Over the years this mercury has flushed its way down into the bay. And it has a tendency like a lot of heavy metal contaminants to bind onto sediment.

It’s such a ubiquitous problem that there’s no way; there’s no technology to either remove or mitigate the effects of those contaminants. Nothing outside of removing millions of tons of sediment, and processing it somewhere that has room for millions of tons of sediment. Most Super Fund sites are infinitesimally small compared to the area the bay covers. For the most part the bay sediment is contaminated almost from top to bottom. What you want to look at is degrees of toxicity. In the areas they are dredging, there may or may not be contaminants at a concentration where they would actually cause harm.

Most of the ferry terminals are obviously going to be near shore where a lot of the contamination problems typically exist, because whatever is being dumped, the first place it’s going to accumulate is right where it enters the bay, from industrial and agricultural and street surface run-off. All the sediment that is going to have to be removed for the construction of these terminals will have to be tested and monitored. Where it goes depends on how contaminated it is. It can be used as land cover, land fill, or just dumped out at a number of different designated dumpsites. Sometimes they dump it in the bay, sometimes out at sea and sometimes upland, depending on what is the most cost efficient way for them to dispose of it. The Federal ocean dumpsite is out at the Farrallons.