In the field of water quality regulation, sewage treatment plant and industrial dischargers often have strict numeric limits on the amount of pollutants they can discharge. In some cases, for highly toxic pollutants like organochlorines and mercury, the limits can be at the parts per billion or even per trillion level.
As a result of the Federal Clean Water Act and the California Porter Cologne Act requirements, most individual sources of pollutants have decreased their toxics discharge by an order of magnitude or more over the last 30 years.
On the opposite side of the regulatory continuum are contaminated sediments.
Contaminated sediment dredge disposal issues continue to be decided by the Army Corps of Engineers, the US EPA, the California Coastal Commission, and the Regional Water Board on a case by case basis. Regulations for open ocean disposal of dredged sediments is pretty strict with disposal limited to a few permitted offsite locations. Toxic sediments aren’t allowed in these ocean dumpsites. However, disposal regulations at nearshore sites are far more ambiguous and a great deal weaker. Since most contaminated dredging activity occurs at marinas and harbors that are the terminus of rivers and creeks, it is surprising that the enclosed quiescent waters of these biologically-critical estuaries would be so poorly protected.
On top of weak regulations governing the dredge and disposal of contaminated sediments, there is no systematic approach to cleaning up California’s worst toxic hotspots. Short of a Superfund or Resources Damages lawsuit (DDT and PCBs off of Palos Verdes as an example), nearly the only way that toxic hotspots get cleaned up in California is through harbor and marina maintenance dredging projects. And as I said previously, the regulations on maintenance projects are on a case by case basis, and disposal decisions are pretty subjective.
In light of lacking toxic hotspot cleanup actions, the San Francisco Baykeeper sued the State Water Board to establish a more standardized approach to contaminated sediment identification and cleanup. As a result, the State Water Board spent a couple of years running a stakeholder process predominantly made up of representatives from ports, harbors and government agencies. Heal the Bay participated for a while, but we found that our pleas for a standardized, objective approach to identifying and cleaning up toxic hotspots were not being addressed.
Instead, the State Water Board worked with the Southern California Coastal Water Research Project (SCCWRP) to develop Sediment Quality Objectives (SQOs) designed to identify toxic hotspots. The SQOs were not to be used for site cleanup decisions (so how do you know when a contaminated site is cleaned up?) or for commonplace contaminated sediment disposal decisions that come up in maintenance dredging projects. Perhaps the narrow utility of the SQOs was due to the genesis and scope of the environmental lawsuit, but the State Water Board missed a tremendous opportunity to develop SQOs that could actually provide clean water benefits including protection of aquatic life and human health outside the scope of the development of Clean Water Act Section 303d impaired waters lists.
In addition, the first phase of the SQO policy relied on the use of three lines of evidence: sediment contamination of the first 5 centimeters, toxicity bioassay results, and benthic community structure (ecological health). The SQO policy recommended use of all three lines of evidence to determine if an area should be listed as impaired or identified as a toxic hotspot. Unfortunately, the system did not lead to an automatic designation when any one line of evidence was clearly a problem. For example, contaminated sediments with hazardous waste levels of DDT, PCBs or lead would not lead to a hotspot designation if the sediments have low toxicity and a relatively healthy biological community. An even more troubling loophole is that sediments could lead to the death of 80% of the organisms in a toxicity bioassay, yet test well in chemistry and benthic ecology and as a result, would not be classified as impacted.
The top five centimeters of sediment test requirement may be more troubling. This approach ignores historic contamination that is still posing a threat to the environment and human health. Under the approved SQO policy, the Palos Verdes shelf Superfund site wouldn’t even be covered because the sediment chemistry in the top five cms isn’t bad, the benthic community structure is pretty good for most of the PV shelf, and the surficial sediments are generally non-toxic. Yet, five species of locally-caught fish from Santa Monica Pier to Seal Beach should never be consumed because of the high levels of contamination of the carcinogens, DDT and PCBs. Clearly, the approach is severely flawed and needs to be amended to protect aquatic life and human health.
To make matters worse, last week, the State Water Board responded to the SF Baykeeper lawsuit requirement to strengthen the SQOs to protect fish and wildlife by amending it to be even more ambiguous and complicated. The SQO Amendments add a narrative objective (example – sediments can’t cause bioaccumulation to toxic levels in fish) rather than a more objective numeric objective (example – 100 parts per billion of DDT). Biomagnification up the food web is a major issue (Palos Verdes Shelf is the classic example), yet the State Water Board wants site by site full blown ecological risk assessments to determine if fish and wildlife are affected by the sediments. This is completely impractical and will result in no additional protection of fish and wildlife from the effects of contaminated sediments.
The State Water Board did ask staff to provide greater clarification of the SQOs in the form of guidance by the end of 2011. This could help, especially if it makes clear that high magnitude single lines of evidence (especially toxicity) can be used to identify hotspots and impaired waters. However, until such time that the Board expands SQOs to include contaminated sediments that are subject to bioturbation (up to half a meter deep) by certain worms and shrimp, and applies the SQOs to site remediation decisions and maintenance dredge disposal actions, California will continue to have numerous toxic hotspots that pose severe ecological and human health consequences.
The result of the SQOs is that the prospects of future contaminated sediment hotspot cleanups looks bleak: a tragic outcome for aquatic life and human health.