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The History of Maryland Septic Inspections and Today’s OSDS Inspection Standards

By: Tim Shotzberger

We can define the standards for today’s onsite sewage disposal system (OSDS) inspection standards as the current law in Maryland; a 1999 statute that says “Anyone performing a septic inspection for the purposes of a real estate transfer must take an approved course by Maryland Department of the Environment (MDE).” 

This guidance has taken septic inspectors in many different directions over the years.  Beginning in 1999, The Maryland Center for Environmental Health Training began offering a class. Anyone could sign up for the 4-hour class which did not have an exam to test students’ knowledge.  Eventually the Maryland Department of the Environment began teaching the class.

This is the class that I took in 2004.  MDE taught us what chemicals enter a septic tank (salt, ammonia, etc.) and what chemicals exit (nitrates).  This would have been very educational if I were a chemistry major looking to do experiments with household wastewater, but I was trying to learn how to do a proper septic inspection.  The guidance was not there.

What constituted a proper inspection was left up to individual septic inspectors.  In the early 2000’s most septic inspectors were structural home inspectors and even termite inspectors who saw septic inspections as a new avenue to make money.  Septic pumpers quickly jumped on board and began offering septic inspections as well, which included pumping or cleaning the tank.  Neither party was doing a very good job at protecting Maryland homebuyers.

Still without much guidance from MDE, some companies started to offer a more detailed septic inspection. They omitted pumping as it was seen as a maintenance procedure versus adding value to the septic inspection.  Soon these companies flourished and saw the void they were filling. The real estate industry needed them. 

They started to cater more towards the needs of homebuyers and the real estate community by improving their reports, ordering process and inspection procedures.

This is around the time that the Maryland Onsite Wastewater Professional Association (MOWPA) formed. They eventually developed a class, manual and standards.  I’m proud to say that I’ve been a part of this process that continues today. Our goal is to develop a better septic inspection and make it conducive to the real estate industry. I’m proud to say that I, along with our Lab Director, Kevin Barnaba, are both instructors for Maryland’s only septic inspector’s course.

These MOWPA standards include inspection all components of a system.  The septic tank should be holding water.  The back baffle should in intact. The distribution box, which is almost always buried 2’ or more below grade, is to be dug open and inspection.  It should be level.  Each drain field or drywell should be receiving the same amount of water.  A hydraulic load test, or water stress test, should be conducted to make sure the system can take water and will not back up.  Records should be requested from the County Environmental Health Department, a homeowner interview should be conducted and the final written report should be a detailed recap of the work that was performed and a log of the observations found.

Most septic inspectors will not offer to pump your septic tank AND excavate the back end of the septic tank and distribution box because it would significantly increase the cost of the inspection. Not to mention that excavating a tank and distribution box is extremely laborious to perform.

MOWPA formed an Inspections Committee who generally agrees that the value of inspecting all of the system’s components outweigh the benefit a homebuyer may receive from pumping the tank at the time of the inspection. A septic pumping may make it easier to determine if a tank is leaking, if a back baffle is faulty or if a drainage system is failing.  However, these issues can also be determined without pumping and requires that the potential home buyer pay far less for the inspection.

MOWPA is currently re-writing their now 8-year old standards to better reflect the most efficient inspections and to better meet the needs of the real estate industry.


Tim is the President and Owner of Home Land Environmental.  A graduate of Salisbury University in 2000, Tim started Home Land in 2004.  He graduated from the Maryland REALTORS® Leadership Academy in 2016 and Tim was selected as the 2017 Affiliate of the Year by the Greater Baltimore Board of Realtors (GBBR). He is on the Board of Directors for GBBR and is active in their Young Professionals Network Committee. He is a member and former board member of the Maryland Onsite Wastewater Professionals Association (MOWPA).  He is an Instructor for the MOWPA Septic Inspector’s Course which is required for all inspectors to perform septic evaluations for the purposes of real estate transactions in Maryland.  Tim also teaches Realtor CEU classes through schools and REALTOR boards all over the state. He is the father of two, and has coached baseball and football, and is the former Treasurer of the PTA.


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