Onsite Disposal Systems

Onsite Systems

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The Onsite Systems Division provides technical assistance and direction to County Health Departments and Local Approving Authorit​ies for the implementation of delegated programs for Onsite Sewage Disposal Systems (OSDS) and individual wells. This is of the utmost importance in carrying out our mission of protecting groundwater quality and public health.

Some of the functions of the Onsite Systems Division are:

  • Co-review of OSDS equal to or greater than 5,000 gpd for compliance with the Large System Guidelines.
  • Provide guidance on the applicability and design of alternative and innovative systems 
  • Provide guidance on the proper interpretation and enforcement of COMAR regulations 26.04.02, 26.04.03, 26.04.04 and 26.04.05, concerning onsite sewage disposal systems, subdivision of land, well construction and shared facilities
  • Provide guidance for site and soil evaluation, construction inspections, and enforcement issues
  • Provide or approve training for sand mound construction, at-grade mound construction, best available technology (BAT) installation, operation and maintenance of BAT systems and inspection of septic systems for property transfers
  • Maintain a list of Individuals who have taken an approved course in the proper inspection of OSDS for property transfer
  • Well Construction inspection and permitting 


Courses offered by the Department and their application forms can be found here.

Site Evaluation for Onsite Sewage Disposal Systems

List of Certified Installers

List of Certified or Approved Individuals

Sand Mound Sewage Disposal Systems

At-grade Mound Sewage Disposal Systems

Guidance for Onsite Systems

For Installers

For Homeowners

Contact Info

If you have additional questions or would like more information, please contact the Wastewater Permits Program, Onsite Systems Division at 410-537-3778.

Additional Information and Related Links