|Dr. Mahler presenting USGS findings|
Dr. Mahler noted that the USGS findings highlighted major land-based sources associated with a trend of increasing PAHs in urban surface water in recent decades, including the finding that coal-tar-based pavement sealant is a much larger source of PAHs to urban lakes than are previously-identified sources (i.e., vehicle emissions, used motor oil, tire particles). While rarely used directly on roads, sealants are often used on parking lots, driveways and playgrounds. Mahler also pointed out that USGS studies had demonstrated excess levels of PAHs in residential dust in homes adjacent to parking lots with coal-tar-based sealants (at concentrations approximately 25 times greater than in residences near other surface types).
Mahler's presentation was followed by a question and answer session. One particularly relevant question (in light of recent Congressional debate on the Federal budget) addressed proposed Administration cuts to the USGS Fiscal Year 2012 budget, in general, and to the NAWQA Program budget in particular. For the 2011 and 2012 Fiscal Years, the President’s budget proposal has included $66.5 and $57.5 million, respectively, for the NAWQA Program, with the 2012 figure representing a $9.4 million reduction below the Fiscal Year 2010 enacted funding level. Those proposed cuts include a $6.7 million reduction from general NAWQA funding and $2.7 million in cuts from publications, administrative costs, travel and the like. USGS is currently evaluating the impact the cuts might have on NAWQA programs. It is noteworthy that while the NAWQA Program has long enjoyed bipartisan support in Congress since its formation in 1991, inflation-adjusted funding for NAWQA has been steadily eroding. Between the 2004 and 2010 Fiscal Years, appropriated NAWQA funding rose nominally from $63.3 to $66.5 million (see Figure 1), an average 0.8% increase per year. However, the average annual rate of inflation during that same six year period was 2.4%.
Established in 1991 by Congress, the NAWQA program mission is to produce surface and ground water quality information for Federal and state resource managers. For example, NAWQA monitoring and modeling of nitrogen and phosphorous loadings to the Gulf of Mexico from the Mississippi River Basin (particularly from watersheds in the Upper Mississippi River Basin) are providing increasingly detailed information to help combat both local water quality degradation and Gulf hypoxia. NAWQA studies conducted in the Chesapeake Bay watershed helped to establish the importance of groundwater discharge as a key Bay nitrogen source, helped to prioritize restoration areas, and provided needed pesticide and nutrient information to the Maryland Legislature to inform its deliberations. A NAWQA nationwide monitoring effort described the extent of MTBE ground water pollution, leading the US Congress and states to remove MTBE from fuel. NAWQA Puget Sound nutrient monitoring results enabled the state of Washington to focus its pollution control efforts in a cost effective manner.
Slides and an mp3 recording from "PAHs Increasing in Urban U.S. Lakes" are available at www.eesi.org/041411_pah. A complete video of the briefing will be also be available soon on-line at the EESI web site. For an overview of all of the USGS research over the years on PAHs and coal-tar-based pavement sealcoat, see here.