When was arsenic banned in California where it was a ingredient in week kill applied under asphalt pavement
According to the University of California Weed Science extension site (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=9603):
‘…because one component of the herbicide is arsenic the use of MSMA has been greatly restricted, primarily due to groundwater concerns. It is currently only allowed for use in cotton and limited use on golf courses, sod farms and highway rights of way…’
Sales for other uses in CA stopped in 2009 and usage stopped in 2010.