Impact of On-Site Wastewater Pollution

Each year over 40,000 new on-site systems are installed in North Carolina for new housing, commercial, and industrial development, adding to the existing 1,440,000 on-site systems already in use in North Carolina. These systems contribute over 360 million gallons of wastewater to the environment every day.

Properly designed and located, on-site systems can be a permanent means of wastewater disposal that protects public health and has minimal effect on the environment. Most on-site systems function satisfactorily; however, a significant number of systems fail to perform as designed, and pressure is increasing to install on-site systems on unsuitable sites. The following statistics indicate the scope of the problem of failing on-site systems in North Carolina.

  • At the time of this publication, approximately 12,600 systems in North Carolina are repaired each year because of failure. Additionally, about 11 % of improvement permit applications are denied, mainly because selected sites are unsuitable.

  • Public health agencies process 62,000 applications per year for site evalua­tions for both new systems and the repair of failing systems. Environmental health professionals perform 136,000 consultative site visits per year, often to inspect a failing on-site system.

These failing on-site systems and unsuitable sites are major concerns.

From the North Carolina Onsite Guidance Manual