NAHB Economics analysis of the Survey of Construction (SOC) data shows that less than 9% of new single-family homes started in 2016 are served by individual wells and close to 16% have private septic systems. These shares, however, vary widely across the nine Census divisions with the corresponding shares reaching 37% and 43% in New England – the highest occurrence rates in the nation.

The SOC classifies sewage disposal systems as public sewers (including community or shared sewage/septic systems) and individual septic systems. Most of new single-family homes (84%) are serviced by public sewers. The incidence of individual septic systems among new single-family starts varies by region.

Close to a half of new single-family homes started in New England have private septic systems, while the national share is 16%. Individual septic systems are also relatively common in the East South Central division and East North Central division where 27% of homes started in 2016 have a private septic system. The share of private septic systems is close but slightly higher than the national average in the South Atlantic division (16.6%) and the Middle Atlantic division where it exceeds 17%.

The common sources of water supply also differ noticeably by geographic location. Similarly to sewage/septic systems, the SOC classifies community or shared water supply/wells as public rather than individual wells. Nationally, close to 9% of new single-family homes started in 2016 are served by individual wells, and the remaining vast majority of new homes are served by a public water system, including shared water wells.

In New England, where new homes sit on nation’s largest lots and are more likely to be custom-built, 37% of new single-family homes are built on individual wells. The reliance on private wells is also relatively common in the East North Central where one in four new single-family homes started in 2016 are built on individual wells. The Middle Atlantic divisions registered the third highest share of homes built on individual wells, 14% – exceeding the national average of 8.9%.

In contrast, individual wells that are not shared are almost non-existent in the East South Central and West South Central divisions where their shares are under 1% and 3%, respectively.

Tags: 2016 starts, community septic systems, home building, housing, individual septic system, individual wells, new single family homes, private septic system, public sewage system, public water system, shared sewage, shared water wells, survey of construction