The report is hard to read, but it states that:
 
"Arsenic  concentrations ranged from 23.5 to 45.1 milligrams per kg in the 36 samples analyzed for this metal.  These concentrations EXCEEDED THE PADEP RESIDENTIAL DIRECT CONTACT MSC of 12mg/kg."  Two to four times the acceptible levels of arsenic- rat poison.

"Eighteen samples from the area of SB08 were analyzed for lead.  Lead concentrations in these samples ranged from 251 to 3,870 mg/kg. CONCENTRATIONS IN ALL BUT ONE SAMPLE EXCEEDED THE PADEP DIRECT RESIDENTIAL CONTACT MSC of 500 mg/kg and the soil to groundwater MSC of 450 mg/kg for this metal."

My guess is that D R Horton bought this land for cheap because it was contaminated.  My guess is also that they were supposed to clean it up before the kids come in direct contact with that soil.

A Montgomery County Maryland jury awarded four Harford County families approximately $100,000 each in punitive damages on March 26, 2008 after finding that D R Horton had not disclosed that wells on their property were contaminated with carcinogenic MTBE.   D R Horton knew of the contamination going so far as to install carbon filtration systems, yet didnt tell the owners of the dangerous conditions.  Once the activated carbon is neutralized, its like taking a shot of wood alcohol.  To see the whole story by Madison Park of the Baltimore Sun:  http://www.baltimoresun.com/news/local/harford/bal-md.ha.mtbe27mar27,0,6350329.story