What is a Phase II Environmental Site Assessment (ESA)?

A Phase II ESA, also called a subsurface investigation, is performed if the findings of the Phase I ESA* indicate the presence of Recognized Environmental Conditions (RECs) at the site. A Phase II ESA typically involves intrusive work such as test borings and monitoring well installations targeted to evaluate for releases of polluting substances at the identified RECs. Samples of environmental matrices (soil, sediment, groundwater, surface water, soil vapor) are collected from the Areas of Concern (AOCs) and analyzed for Substances of Concern (SOCs). Analytical data received from the laboratory is compared to applicable regulatory criteria to determine whether a release has occurred. If the data indicates that a release/adverse impact to the environment has been detected additional investigations may be warranted.

CCA is uniquely equipped to assist our clients in timely Phase II ESAs as we are one of the few consulting firms in Connecticut that own and operate our own soil boring equipment. CCA owns a GeoPROBE® 54LT Direct Push Soil Boring rig that we use for shallow soil and groundwater investigations in unconsolidated overburden areas. Self-performance of this investigation work saves our clients' money (our day rates are very competitive and we do not charge a mobilization fee – most contractors charge to mobilize to a job site) and just as importantly TIME, since we are not at the mercy of subcontractors schedules which sometimes can add weeks to a subsurface investigation. Of course, we maintain long standing relationships with several professional drilling companies and utilize their services as dictated by site conditions.

All ESA work at CCA is performed by or under the direct supervision of a Connecticut Licensed Environmental Professional (LEP). Please feel free to contact Mr. Ralph A. Klass P.E., L.E.P. at ralphklass@ccaengineering.com or 203-775-6207 if you would like to request a quotation for ESA services or if you have any questions regarding the services CCA can provide.


Recognized Environmental Concern (REC) – Can be defined as "the presence or likely presence of any hazardous substances or petroleum products in, on, or at a property: (1) due to release to the environment; (2) under conditions indicative of a release t o the environment; or (3) under conditions that pose a material threat of a future release to the environment.

Area of Concern (AOC) – Locations or areas at a site where hazardous waste and or hazardous substances (including petroleum products) have been or may have been used, stored, treated, handled, disposed, spilled, and/or released to the environment.

Substance of Concern (SOC) – An element, compound, or material that has the potential to be released to the environment.

*See additional FAQ answer sheets for the definition of Hazardous Waste Establishment, Phase I ESA, Phase III ESA and Licensed Environmental Professional (LEP).