Backflow Corporation of New York Share: ENVIRONMENTAL Backflow Corporation of New York Visit Website PO Box 455 Greenlawn, NY 11740 (631) 261-8622 (631) 261-9716 (fax) www.longislandbackflowpreventers.com About Rep Info Map About Plumbing, Air conditioning and heating. Back flow needs and inspections Whom to Contact Eric Christensen What's Nearby? Distance: 5 10 15 20 25 50 mi.