240 N. Broadway, Suite 203
Portland, Oregon 97227
(503) 847-2740

EES Environmental Consulting, Inc.
Heidi Yantz

Heidi Yantz, RG, LHG, PG

Principal Hydrogeologist [email protected]


Heidi Yantz has 19 years’ experience as an environmental hydrogeologist with site assessment and cleanup activities performed on sites ranging from urban facilities to rural properties. Her success at managing projects stems from more than 30 years of business experience managing people and budgets and implementing a broad range of work scopes. In recent years, Heidi has specialized in providing senior technical support and QA/QC oversight on longer-term and more technically complex sites. She manages multi-discipline projects that require coordinating efforts with attorney teams as well as various project stakeholders, and she works closely with clients to provide options and recommendations that address business needs and encompass financial and technical constraints as well as regulatory requirements. Many of her current and past projects have been conducted as part of voluntary agreements and in cooperation with regulatory agencies including the Oregon Department of Environmental Quality, Washington Department of Ecology, and the U.S. EPA.


  • Conducts investigations for contaminants such as chlorinated solvents, petroleum compounds, heavy metals, and pesticides/herbicides, and works with stakeholders to obtain regulatory closure or compliance. Heidi has designed and participated in cleanups ranging from soil excavation and groundwater pump and treat to a variety of in situ treatments.
  • Has performed Phase I ESAs since 2000, with approximately 75 assessments completed as the primary assessor and over 100 as a senior reviewer or technical resource. Sites ranged from heavy industrial facilities to small commercial lots, and from single and multi-family residential to large tracts of vacant land.
  • Conducts investigation, assessment, and remedial activities on closed permitted and historical unpermitted landfills. Activities have included landfill gas investigations, groundwater monitoring programs, landfill cover evaluation, O&M plan preparation, and financial assurance estimates and letters.
  • Works on environmental tasks for infrastructure and construction projects, including preparation of contaminated media management plans, corridor hazardous material assessments (roadways), and health and safety plans.
  • Serves as project manager for insurance-paid projects primarily as the insured’s consultant. In these projects, Heidi works closely with defense and coverage counsels and the insured to develop appropriate strategies, scopes, and funding prior to initiating activities.
  • Ranks safety as a key component to a successful project. Heidi has prepared and reviewed HAZWOPER-compliant health and safety plans (HASPs) and construction-oriented HASPs and has developed and delivered programs to facilitate onsite worker training. She has led corporate safety programs, coordinated substantial revisions of corporate safety plans, and developed programs to mitigate risk to employees.


  • M.S., Geosciences, University of Wisconsin-Milwaukee
  • B.A., Business Administration, University of Washington


  • Oregon Registered Geologist (#G2152)
  • Washington Licensed Hydrogeologist (#2685)
  • Idaho Professional Geologist (#1256)
  • HAZWOPER 40-hour Training
  • HAZWOPER Supervisor Certification


Heidi has delivered presentations on environmental assessment, cleanup, and management at regional conferences, and moderates panels on the state of the environmental practice. She serves on steering committees for regional technical conferences, and participates in brownfield-related advisory committees for the City of Portland and Oregon Tradeswomen Inc.

  • Northwest Environmental Business Council, Board Member
  • Women in Environment, Former Board Member
  • Geological Society of America, Member
  • National Groundwater Association, Member