CONTACT US  (406) 549-5022

  • Feasibility Studies of private or public septic, sewer, and water systems

  • Commercial and Residential Site Plans for building permits

  • Septic Permitting Applications submitted to Health or Department of Environmental Quality (DEQ) 

  • ​Site evaluation and soil analysis for septic sites

We can help in these areas:​

Design - approval - inspection - monitoring, and finally, sign-off in the following infrastructure improvements:

  1. ​Sewer & Water main extensions
  2. Sewer and Water services
  3. Roads, curb/gutter, and sidewalks
  4. Culverts, ditches, sumps and other drainage structures
  5. Hillside design of infrastructure


  • Percolation Tests and Septic Design

  • Ground water monitoring applications for septic feasibility

  • Ground water mapping for determining direction of flow

  • ​Water quality testing for new or existing wells

Our engineering professionals create and design plans accurately and on time


Eli & Associates has been providing exceptional civil engineering and site development services to our clients for over 30 years. We present plans to city, county, state and federal agencies.  Our designs prioritize sustainability and environmental health.

Civil Engineering