ADL is lead left behind from years of leaded gasoline use. On old roads like 101 that have been in existence since the early 1900's, lead was continuously deposited from the tailpipes of cars and poorly combusted leaded gasoline. This lead ended up in either the surrounding soil or moving downstream. In areas with thick canopy cover and deep rich soil, like Richardson Grove, much of the lead remained in the soil and usually ended up between 6 and 24 inches underground. The top six inches are usually lead free, as this is duff and recent soil accumulation post leaded gasoline.
Lead serves no purpose in our bodies and is dangerous to all living things. It is toxic to numerous organs and biological functions, including the heart, bones, intestines, kidneys, and reproductive and nervous systems. It is especially toxic to children, causing potentially permanent learning disabilities and behavior disorders. There is no safe threshold for lead exposure, no amount small enough to not cause harm. We all carry a pre-existing body burden of lead in our bones, blood and tissue, and unless specialized therapys are undertaken, it remains for life. That is why hazardous waste guidelines for lead exist. In Richardson Grove, levels of lead were found in many places to be above hazardous waste levels, and other places just slightly below. Considering how sensitive a state park like Richardson Grove is, with familys camping and people strolling about throughout the year, and automobile traffic up 101, one would think that CalTrans would care about the potential for exposing people to lead. They don't.
Removing leaded hazardous waste from roadsides requires great care and large amounts of money. Care and money that Caltrans doesn't have. This is why Caltrans is doing their best to avoid listing areas in the state as hazardous waste sites. They are doing this by either raising the allowable limits 30 times current standards in non sensitive areas. Or in the case of Richardson Grove and other sensitive areas, fudging the books and manipulating data collection. They did this in four ways;
1) Caltrans tests every six inches and then combines these together for a "Total Threshold Limit Concentration" (TTLC). If the combined levels exceed 5 ppm soluble lead its hazardous waste. Their rationale for using this dubious method is that all of the removed soil will be mixed up into one mass by the projects end. However, in the case of Richardson Grove, the project calls for excavating down 24" (except for new wall pillars that go much deeper), yet Caltrans only tested down to the 18" depth, avoiding the area with potentially the greatest concentration of lead. Caltrans website states that “Aerially deposited lead is typically found within the top 2 feet of material in unpaved areas within the highway right of way”.
2) The top 4 inches, which are lead free, were added to the mix to come up with a TTLC that was just under haz waste criteria. Yet this soil will not end up with the rest of the soil and shouldn't have been added. The FEIR states "The top 4 inches of duff (redwood tree and Douglas fir leaf litter) shall be removed, stored at a staging area location and subsequently spread out on exposed disturbed soils within the park boundary."
3) Caltrans never tested the area where the new wall is going and where the deepest excavating is to take place.
4) Caltrans used an inaccurate test method. Even though Caltrans has always prided themselves as being more protective from hazardous lead exposure than other states because they use a test method known as CA-WET (CA=citric acid), for Richardson Grove they used a method called Di-Wet. This method is known for being inaccurate, so much so that in 2007 WQCB issued a memorandum and action alert that stated “analytical data from the Waste Extraction Test (WET) performed with deionized water as the extractant (DI-WET) were used to classify a waste stream as non-hazardous. When samples of the waste were subjected to the correct version of the WET (using citric acid as the extractant), it became clear that the waste had been improperly tested initially and may have been inappropriately accepted for discharge to a landfill that was not permitted to accept hazardous waste. As a result, the owner and operator of that landfill may face significant enforcement proceedings and expensive corrective action measures.”
For Caltrans to honestly evaluate the potential for lead hazardous waste, they need to retest to the depth of 24”, the need to test the new wall site, they need to exclude the 0-4” horizon from the TTLC and they need to use their normal method of CA-WET when they test. But even then, the question will remain, will they manipulate new testing as well. Since the answer is probably yes, the testing should instead be done by an independent agency that can be trusted.
Dan Zimmerman / Environmental Investigator / Northcoast Ocean and River Protection Association (NORPA)