Yerkes Associates, Inc; 1444 Phoenixville Pike, West Chester, PA 19380
Yerkes Associates, Inc.; offering professional services since 1874; Consulting Engineers/Site Planners/Surveyors
Yerkes Associates, Inc Services

Our staff of over 50 professionals turn your ideas into reality. You are involved in the planning process, clearly defining your needs so we can achieve the results you expect-on time and within your budget. With your criteria in mind, we recommend long lasting, cost effective solutions. After you choose the best option, we engineer and design your project from start to finish.

site planning and land development

Yerkes' careful site planning and design minimizes construction costs and maximizes project profitability. By incorporating our capabilities for civil engineering and surveying, the resultant integrated plan enhances the value of your site and the aesthetics of the property.

Representative Clients

  • Bryn Mawr College
  • Bryn Mawr Hospital
  • Chester County Hospital
  • Great Valley Corporate Center
  • Lankenau Hospital
  • Marriott Hotels
  • PNC Bank
  • Plymouth Meeting Mall
  • Quarry Ridge Corporate Center
  • The Rouse Company
  • Exton Square Mall
  • Villanova University


Yerkes prepares complete subdivision plans, documents and legal descriptions which result in efficient processing of all zoning, technical and legal compliance matters.

Representative Clients

  • Chesterbrook
  • M & Z Builders
  • Villas at French Creek
  • Waynebrook

stormwater management

A major requirement of land development is the design of adequate stormwater management facilities for new projects, and the redesign of inadequate or deteriorated facilities. Yerkes' innovative stormwater management designs can increase a site's buildable area and enhance land values. We also produce floodplain studies, erosion control and storm drainage designs, irrigation and water resource development plans.

Representative Clients

  • Bryn Mawr College
  • Devon Motors
  • Liberty Property Trust
  • Wyeth Ayerst Laboratories

municipal engineering

Yerkes provides municipalities and municipal authorities with complete consulting services: plan reviews, road and utility construction inspections, plan and specification preparation, ordinance and 537 Plan preparation and updating, storm and sanitary sewer system designs and expert testimony in matters relating to subdivision and land development.

Representative Clients

  • Aston Township
  • Birmingham Township
  • East Bradford
  • East Brandywine Township
  • East Goshen Township
  • Easttown Township
  • Edgmont Township
  • Narberth Borough
  • Newlin Township
  • New Morgan Borough
  • Norristown Borough
  • Pocopson Township
  • Radnor Township
  • Schuylkill Township
  • Thornbury Township
  • Warwick Township
  • West Caln Township
  • West Goshen Township
  • West Marlborough Township
  • West Nantmeal Township
  • West Pikeland Township
  • Willistown Township

wastewater collection and treatment

Yerkes offers comprehensive service in wastewater management. From feasibility reports to plans and specifications, we design pumping stations and treatment facilities and operate sewage systems and community on-site systems. We have developed innovative technology in the application of Drip Distribution to medium and large volume sewage treatment systems.

Representative Clients

  • Nantmeal / Warwick Joint Sewer Authority
  • Orleans Home Builders
  • Radnor Township
  • Thornbury Township
  • Toll Brothers
  • Willistown Township
  • New Morgan Utilities Authority
  • Westtown School

feasibility studies

The first step for many projects, our feasibility studies analyze the scope of the project, investigate alternatives, plan staging or phasing of the work, estimate costs, suggest financing and determine timing. Feasibility reports are prepared as a part of a total project or as a separate study.

Representative Clients

  • Bryn Mawr College
  • Friends Central School
  • Haverford College
  • Rosemont College

highways, streets and bridges

Yerkes complete design services include alignment studies, right-of-way surveys, facility design plans, and planting and stabilization plans.

Representative Clients

  • Chesterbrook PRD
  • City of Coatesville Road Improvement Program
  • Easttown Township Road Improvement Projects
  • Exton Square Mall
  • PennDOT R.R. Track Realignment at Vanguard
  • Thornbury Township, Chester County


Yerkes was established in 1874 to provide land surveys, and now performs more than 500 each year. Projects range from small parcels in Chester County not surveyed since colonial times to city tracts where multiple property lines and air rights at different levels are in question. Surveying services include boundary surveys, topographical work, construction surveys and as-built surveys.

Representative Clients

  • Great Valley Corporate Center
  • Lankenau Hospital
  • Plymouth Meeting Mall
  • SAP America
  • American College
  • Villanova Law School
  • Fort Mifflin
  • Bryn Mawr Hospital

construction layout

Yerkes extensive experience covers all phases of construction stakeout for subdivisions, sitework, structures and special alignment projects.

Representative Clients

  • David Cutler Group
  • Turks Head Kennett Medical
  • E.B. Mahoney Builders, Inc.
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