North Woodmere and Mill Brook.
Wikipedia says South Valley Stream is an unincorporated hamlet made up of two areas, North Woodmere and Mill Brook, and that Green Acres Mall sits on its border with the Village of Valley Stream. The CDP covers 0.9 square miles, all land.
The Census Bureau's latest five-year survey counts about 1,900 homes, with a median year built of 1956. 56% went up in the 1950s, 14% before 1940, and 6% after 1980. 81% are single-family detached houses, 10% are in buildings of five or more units, and 85% are owner-occupied.
So a typical house here has drain and water lines around 70 years old unless they've been replaced. Slow drains in several fixtures, a gurgling floor drain or rusty water from one tap are signs to have the main line and supply piping checked.
Oil to gas means new gas piping.
The ACS shows 48% of homes heat with utility gas and 45% with fuel oil. Switching means properly sized gas piping to the new equipment, and often to the water heater, range and dryer. We do the gas line work. We don't sell or deliver oil.
Sewer.
Nassau County's health department list of sewer collection districts doesn't name South Valley Stream separately; Valley Stream and North Valley Stream next to it are both listed under the Nassau County Department of Public Works (516-571-6841). A sewer district charge on your tax bill means you're connected. A backup that stops at your house is usually in your own line to the street; we clear it and repair or replace the line. If neighbors are backed up too, call the county at 516-571-6841.
Flood risk.
Laying FEMA's current flood map over the Census boundary, about 44% of South Valley Stream is in the high-risk (1% annual chance) flood zone (44.3% in zone AE; shares of the Census area, water included). On a sewered street, a backwater (sewer check) valve on your house sewer line can keep a street-sewer backup from coming in through basement floor drains. We install them. If your water heater or gas appliances ever sat in flood water, have them checked before relighting.
Water: Liberty Utilities New York's Lynbrook system.
EPA's service-area map puts essentially all residents on Liberty Utilities New York's Lynbrook system; your bill is the final word. Liberty's 2026 report on 2025 water for its Lynbrook Operations District says caustic soda or lime raises the pH to cut corrosion of household plumbing and iron is filtered out at 13 of its 20 well sites; total hardness ran 4.2 to 58.6 mg/L, which is soft. Across the whole district, Liberty's state-filed inventory counts 3,700 lead service lines and 15,239 of unknown material, so if your house predates 1940 it's worth knowing what your service line is. In EPA's UCMR 5 testing, the main supplier's highest single PFOA/PFOS result was 5.1 parts per trillion. EPA's 4 ppt limits apply as a running annual average starting in 2029, so one high sample is not a violation, but it's the kind of number a carbon filter is sized against. For a leak at the curb or in the street, call your water supplier. For anything on your side of the meter, call us.
Permits.
South Valley Stream is an unincorporated hamlet, so plumbing permits go through the Town of Hempstead Building Department (One Washington Street, Hempstead).
