My Neighbor's Had A Sewerage Crisis, Which I Think Spread

My neighbor's had a sewerage crisis, which I think spread to my yard. Not sure if it is related, but now my dog is getting treatment for mange. I started severely itching, particularly at night, exactly the next day after returning from the veterinary clinic. My son is home from college and seems not to experience itching symptoms. I am using a medicated lotion for lice. It does reduce the itching, but has not cured my itching. Please help! Thank you.