Subsurface Wastewater Licensing & Certification


Page Index

Site Evaluator Licensing

Installer/Inspector Certifications

Please note:  The Maine Drinking Water Program/Subsurface Wastewater Unit does not license Local Plumbing Inspectors (LPIs), nor do we appoint LPIs to municipal posts. For information on LPI licensing, contact the Maine State Fire Marshal’s Office.


Site Evaluator Licensing



Subsurface wastewater disposal systems are used extensively throughout the State of Maine to treat and dispose of domestic and commercial wastewater. Maine, being primarily a rural state, relies largely upon small subsurface wastewater disposal systems. Municipal wastewater systems often are uneconomical, unfeasible, or unavailable.

Soil percolation tests were utilized prior to 1974 in Maine to determine the suitability of the soil and the appropriate design of the disposal system. The Department of Health and Human Services, Division of Environmental and Community Health (then known as the Division of Health Engineering) which is responsible for administering and enforcing the Maine Subsurface Wastewater Disposal Rules, experienced significant problems with this method of determining soil suitability. The increasing rate of malfunctioning disposal systems, coupled with development of unsuitable areas, created the potential for an escalation of health hazards, nuisances and environmental degradation.

The concept of site evaluation for wastewater disposal system design began in Maine in the early 1970's as an improved and more reliable method for determining soil suitability. Rules requiring on-site soil evaluations for design of all subsurface wastewater disposal systems became effective in July, 1974. 

Maine requires that individuals who design disposal systems be licensed. Maine's Department of Health and Human Services, Division of Environmental and Community Health administers the licensing of these individuals. A person who is interested in becoming a Site Evaluator must have an educational background and experience that indicates to this Department that he or she has a knowledge of soils and subsurface disposal design. Qualified individuals are permitted to take a written examination to prove they have the necessary skills and knowledge to do the design work correctly. After successfully completing the written examination, they are permitted to take the field examination to illustrate their proficiency in soil profile description and classification which is necessary for disposal system design.

Site evaluation combines on-site soil evaluation with consideration of site conditions. Licensed Site Evaluators are required to have the skill and ability to properly identify and accurately report soil textures and limiting factors so they can adequately classify soils, recognize site limitations and properly size disposal systems.

For more information, contact State Site Evaluator Brent Lawson:  Email or phone (207) 592-7376.


Site Evaluator Exam Application

The Site Evaluator's Examination Application requires the following information:

  1. Educational background with a description of any completed courses pertaining to soil evaluation or subsurface wastewater disposal.
  2. Work experience involving soil investigation or subsurface wastewater treatment design.
  3. Three (3) references shall be submitted by persons who have a professional knowledge of the applicant's work, one of which shall be a Licensed Site Evaluator.
  4. The applicant's request for examination, along with the completed application and reference forms, must be received by the Department no later than 30 days prior to the examination date.
  5. An application fee of $25.00 dollars shall be submitted with the application and is non-refundable.

Site Evaluatior Application Packet Forms


Qualifications: Education or Experience

  1. Education
    • A graduate from an accredited college or university with an undergraduate degree in engineering, geology, pedology, or similar disciplines.
    • Twelve [12] months or more of experience which indicates that the applicant is competent to perform site evaluations.
  2. Experience
    • Must have a high school education or equivalent.
    • Four [4] years or more of experience which indicates that the applicant is competent to perform site evaluations.


  • Only qualified persons will be admitted to the examination.
  • Examinations shall be held on dates and places as determined by the Department, but in no case shall the Department hold less than one [1] examination per calendar year.
  • The examination consists of written and field portions which focus on the principles and practices of Site Evaluation. Either portion of the examination may be taken prior to the other.
    • The written portion will test the applicant's knowledge of soils and familiarity with the Code and will consist of three parts: 1) Rule requirements, 2) Soils, and 3) System Design. A copy of the Code may be used as a reference during the examination. The fee for the written portion of the exam is $25, payable prior to each exam session.
    • The field portion will test the applicant's ability to identify soils with regards to parent material, textural classification, drainage conditions, and depth to limiting factors in accordance with the Code. The fee for the field portion of the exam is $75, payable prior to each exam session.
  • The passing grade for both portions shall be a score of seventy [70] unscaled.
  • Applicants failing two or more sections of the written exam must re-take the complete examination at the next scheduled date. Applicants failing one section of the written exam may re-take the failed section at a date scheduled by the Department. An applicant who fails to pass a failed section after two tries must re-take the complete written examination.
  • An applicant who passes either the written or field portion of the exam, but fails the other portion, must take the entire exam again, unless the applicant successfully passes the failed portion within twenty-four (24) months.


  • The Department shall issue a license to an applicant who passes both portions of the examination.
  • Licenses shall be renewed the first day of March of each odd numbered year by submitting the updated correction card and licensing fee.
  • A Site Evaluator who allows a license to lapse may renew it any time during the following two (2) year period, provided his/her record of conduct is acceptable to the Department. Failure to renew a license after the two (2) year grace period shall require a re-examination.
  • A Site Evaluator shall not perform site evaluations with an expired license.
  • The license fee is one hundred [$100.00 US] dollars for a two [2] year period; and beginning with the 2007-2009 licensing period, each licensee shall earn a minimum of twelve (12) professional development hours within each license period in order to obtain license renewal.
  • Please contact the Division if you would like to have a a Site Evaluator application packet sent to you, or download the following documents.

Documents for Download



The Subsurface Wastewater Team offers voluntary certification programs for Certified System Inspectors and Installers.

Onsite Sewage Disposal System Inspectors

The Division of Environmental and Community Health has established minimum criteria for evaluating and reporting on existing subsurface wastewater disposal systems. This voluntary program is being promoted as an important component of the real estate transaction process, and is required by law in the shoreland zone. Please see details in Sections 15, 16, and 17 of the Maine Subsurface Wastewater Disposal Rules, 10-144 Chapter 241. Click here to learn more.


Onsite Wastewater Disposal System Installers

The Division of Environmental and Community Health has developed a non-regulatory incentive driven program to broaden the use of proper septic system installation techniques, for individuals who install onsite wastewater disposal systems.  A secondary purpose is to recognize installers who make an effort to educate themselves on these techniques and to provide an incentive to continue education efforts on proper installation techniques.  Click here to learn more.

Updated 12/26/2023