Sanitary Engineering Notice

Permit Center services are being conducted by appointment.
For more information, call Perc Testing: 410-222-7193,
Septic Installations: 410-222-7194 or Water Wells: 410-222-7398.

Requirements for Best Available Technology (BAT) in the Chesapeake Bay Critical Area

Last updated: July 27, 2022

What are the requirements?

The Code of Maryland Regulations COMAR 26.04.02 establishes requirements for on-site sewage disposal systems within the Chesapeake Bay Critical Area. Effective November 24, 2016, State regulations amended the requirements for Best Available Technology (BAT) for properties within the Chesapeake Bay Critical Area. The requirements apply to permit applications for septic tanks, drainfields, drywells, sand mound systems, pressure dosed beds and any other type of on-site sewage disposal system on a property in the Chesapeake Bay Critical Area. New Construction or the replacement of septic systems outside the Critical Area are not required to install a BAT with the amended State regulation.

More information about NRUs is available by visiting Non- Conventional Systems – Frequently Asked Questions.

What type of unit is required?

The regulation establishes Best Available Technology (BAT) for removing nitrogen. A list of pre-approved BAT units is available at the Maryland Department of Environment, Onsite Disposal Systems. Only pre-qualified licensed disposal system contractors may install a NRU.

What other requirements apply?

The property owner is required to operate and maintan the BAT for the life of the system through a certified service provider. The owner shall ensure the BAT system is inspected and has necessary operation and maintenance performed at a minimum of once per year.

What information must I submit to the Department of Health to install a BAT unit?

A site plan of the property and a completed Perc Application with appropriate fees must be submitted to:

Permit Center
2664 Riva Road
Annapolis, Maryland 21401

Online Registration for Perc Application – Department of Inspections and Permits

More information is available by visiting Perc Testing Procedures Where On-Site Septic Systems are Proposed.

What programs are available to assist property owners with the cost of installing a BAT unit?

The Bay Restoration Fund provides grants to property owners to cover part or all of the cost for the nitrogen-reducing unit. Based on the availability of funding, applications are processed on a first-come, first-served basis with priority given to the repair or replacement of failing septic systems within the Critical Area. More information is available by visiting Bay Restoration Fund. Or, to apply for a Bay Restoration grant, see Grant Application for Nitrogen-Reducing Pretreatment Unit.

The Linked Deposit Loan Program discounts the loan interest rate to install a nitrogen-reducing system or to repair or replace a failed septic system. More information is available by visiting Linked Deposit Loan Program.

The Well and Septic System Assistance Program helps income-qualified applicants repair or replace failing septic systems. More information is available by visiting Well and Septic System Assistance Program.

Where can I receive additional information?

For more information, contact:
Anne Arundel County Department of Health
Environmental Health
Sanitary Engineering Program
3 Harry S. Truman Parkway
Annapolis, MD 21401

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