How much sand waste do you have? Under the EPA definitions if you generate less than 2200 lbs of hazardous waste per month you are a "conditionally exempt small quantity generator" and can legally send your waste to a subtitle D landfill (most municipal landfills). Some landfills and some states however have more strict limits of their own.
It's a hazardoue waste only if it fails the TCLP leachate test.
The EPA exempts household lead based paint (LBP)waste generated from household activities but again some states and landfills have more strict requirements. Their definition of household LBP is written for building renovations and repairs.
Mixing with concrete (I think it actually says Portland Cement in the regs.) is one of the EPA approved technologies for "solidification" waste treatment. Treatment facilities that do this have to prove it passes the TCLP test after solidification but it's a very commonly used treatment method.
