Rapid population growth has led to decentralized sewer practices in the unincorporated areas of St. Tammany Parish.  Installation of thousands of individual Aerated Treatment Units (ATUs) and septic tanks have led to the decline of surface water quality in the Parish. In unincorporated areas and in older neighborhoods, individual on-site treatment units are operated and maintained by the homeowner.  Few systems receive proper maintenance because homeowners are either unaware of the need for maintenance or find it a distasteful task.  Many systems are old, inadequate, in poor condition, and not designed to meet today’s more stringent design standards.  Individual ATUs can and do provide a satisfactory level of water quality protection, but only if they are properly operated and maintained.
There are areas in the Parish where it is not feasible to provide regional sewage treatment facilities.  A decentralized management approach will provide a solution to achieve measureable water quality improvements within the Parish.  The overall goal of the decentralized management program is the protection of public health and water resources by ensuring that existing and future on-site wastewater treatment plants are properly operated and maintained, especially in those areas with known degraded water quality.  With the appropriate level of management to these treatment units, pollutant loads on the watershed can be reduced to achieve water quality standards.
The Decentralized Management Plan will implement a series of elements and activities that will address public education and participation, planning, performance, operations and maintenance, corrective actions, recordkeeping/inventory oversight, reporting and financial assistance funding. 

A Point Source discharge is a single identifiable source of pollution, such as a pipe or drain commonly discharged into drainage infrastructure & waterways. Many point source discharges in St. Tammany Parish originate from Wastewater Treatment Plants (WWTP) and are permitted and monitored by the Louisiana Department of Environmental Quality (LDEQ).
Common Point Source Discharges are as follows:
Municipal WWTPs
Small Subdivision WWTPs
Industrial Wastewater
Illicit discharges (unpermitted discharges)