About Us

With over 65 years of combined experience in all phases of site development, Harborstone Consulting, LLC  is qualified to handle your project from site feasibility through project completion.

Through our years of experience in the real estate development industry, Harborstone Consulting, LLC has developed excellent working relationships with architects, engineers, environmental consultants, land-use attorneys, land surveyors, contractors and other professionals who can be recommended as a member of a project team.

Mike has more than 40 years of experience in septic system engineering and installation and residential and commercial site development.  

Mike is a Washington State licensed on-site septic designer.  He applies his knowledge, experience and a no-nonsense approach to engineering septic systems that are best suited for the site.  Mike provides onsite septic engineering services for both residential and small commercial projects.

Mike Jerkovich

​​WA State Licensed On-Site Septic Designer



Kathryn Jerkovich


Land Use Consultant | Permit Specialist

Licensed Real Estate Broker



Kathryn has been involved in real estate development in some capacity for more than 25 years and specializes in all aspects of land use consulting, construction permitting, and project feasibility for both commercial and residential projects.  

In addition, Kathryn manages and oversees the day-to-day operations of the company.

She also currently represents District 7 on the Pierce County Planning Commission and is a licensed real estate broker with Windermere Real Estate Gig Harbor.