Onsite Engineering, PLLC is focused on the design of decentralized wastewater treatment systems.  We work on commercial and residential projects ranging in size from single family residential to over 20,000 gpd.  As a specialist in onsite wastewater, we commonly team up with other engineering firms to provide our technical expertise.  


Our Mission

Provide simple and smart septic designs using a variety of approaches to efficiently address the challenges of the site.


Although there are many common features amongst various septic designs, it is very important that each design is specific to the property that it is being installed.  We focus our attention on the limiting conditions that prevent a septic system from achieving new construction standards outlined in Appendix 75-A of the State Sanitary Code.  These limiting conditions can include the inability to meet horizontal or vertical separation distances to seasonal high groundwater, surface water, or drinking water supply wells.  We develop septic designs using the simplest technology possible, while considering these site limitations.  The design gets more complicated if the site has other restrictions including small size, steep slope, or poor soil for biological treatment.

Onsite Engineering has completed over 1,000 designs using 34 different types of systems and has long since been regarded as a pioneer in the septic industry throughout New York State.   Our designs and innovative approach to simplicity have been published in many articles in national publications.  We were showcased as the cover article in Onsite Installer Magazine in April 2013.  Over a dozen articles have been written about our company and innovative designs.  If the conditions are right – we keep it simple and use gravity all the way.  Additional measures must be taken to treat the wastewater and protect the drinking water resource if poor soil is present.  

Our designs provide wastewater treatment performances equal to or greater than central treatment plants and small packaged treatment plants.  We also provide expert alternative decentralized wastewater treatment engineering studies for small communities, developers and civil engineering firms.

additional services

  • Designing repairs or replacements for failing onsite septic systems for commercial, municipal and residential clients.
  • Inspection and maintenance services for commercial, municipal and residential onsite septic systems.
  • Decentralized wastewater treatment solutions for restaurants and other high strength effluent facilities.
  • Designing solutions to meet higher treatment standards for nutrient (nitrogen and phosphorus) reduction levels.
  • Low cost environmentally sound decentralized treatment solutions for new developments and subdivisions.
  • Stormwater treatment designs with an emphasis on treated stormwater resuse wherever possible.
  • Decentralized wastewater treatment education and training for architects, contractors, engineers, municipalities and regulatory officials.