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About Us

About Clean Soils

Clean Soils Environmental, Ltd. (CSE) is a customer-focused environmental consulting company that specializes in Licensed Site Professional (LSP) services concerning the assessment, management, and remediation of oil and hazardous materials throughout Massachusetts and the New England region. Since 1989, we’ve provided cost-effective solutions to a wide range of environmental challenges in full compliance with all regulatory requirements. Our highly qualified, personable, and motivated staff work with our clients to navigate the maze of State and Federal regulations in order to find innovative and cost-effective strategies oriented towards a permanent solution.

To provide the greatest degree of flexibility and personalized service, CSE regularly teams with other well respected professional companies and experts to provide tailored solutions to a wide variety of environmental challenges. By using independent firms to provide contractor services, there is no motivation to call for excessive sampling or unnecessary remediation. CSE succeeds in achieving regulatory compliance for its clients by taking the lead role in developing remedial goals and implementing closure strategies as the Project Manager and LSP, while coordinating and directing contractors who perform the specialized field tasks often required during assessment and remedial response actions.

The result is a team of specialized professionals working together to provide our clients with options and cost-effective solutions to reduce environmental liabilities and achieve regulatory and business objectives in a timely and concise fashion. Our clients can rest assured that environmental investigations and remedial activities are conducted efficiently at the lowest cost. By working with CSE, the client will get the personalized and rapid service that a smaller firm can deliver, while gaining access to specialized resources required for complex projects.

Our clients cover a wide range of sectors including residential homeowners, commercial and industrial property owners, financial institutions, insurance companies, contractors, developers, trucking companies, engineering firms, educational institutions, non-profit organizations, municipalities, and state and federal agencies. Our projects range from small residential oil spills to widespread industrial facility releases.

CSE understands that environmental problems are generally unforeseen and are not the focus of your business or project. We take the time to educate our clients in order to guide them with informed solutions to their environmental problems. CSE will serve as an advocate for our clients and negotiate with insurance companies, regulatory authorities, and the public. CSE’s opinions and recommendations are always clearly stated and are relied upon by mortgage lenders, insurance companies, and government agencies. Our work and relationships with clients, partners, and our own employees are based on high standards of safety, as well as personal, business, and professional honesty, integrity and ethics. Doing business this way creates mutual trust. Relationships built on such solid foundations enable successful projects.

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Our Mission

CSE is committed to providing professional, pragmatic, and cost-effective solutions to environmental and regulatory compliance challenges. CSE strives to reach this goal by retaining knowledgeable individuals with integrity in order to provide our clients with quality work, attention to detail, rapid responses, and creative solutions for difficult technical problems. CSE is an agile, responsive firm that can react immediately to the changing conditions and requirements of a project. Each member of our well-trained and experienced staff is a decision-maker so that clients do not have to wade through layers of bureaucracy for answers or accountability. At CSE, we do our utmost to educate our clients, which takes the uncertainty out of the assessment and cleanup process.

CSE’s clients can expect practical solutions and honest, straightforward answers. We pride ourselves on our technical expertise as well as outstanding management practices, which result in cost efficiencies for our clients. In an industry where technology and regulations are constantly evolving, CSE is vigilant about maintaining the most advanced equipment, while requiring ongoing education for our staff in the latest tools, techniques and regulations. We abide by all appropriate regulations and procedures mandated by the Department of Environmental Protection, the Environmental Protection Agency, and the Occupational Safety and Health Administration to assure the safety and quality of our work.

Our History

Clean Soils Environmental, Ltd. (CSE) was founded in 1989 by Denise M. Prosser. Ms. Prosser was then attending New Hampshire College to obtain her MBA. Her final project entailed researching new business horizons to develop a family business. The environmental consulting field was approximately 5 years old in 1989 with a vast growth potential. With this in mind, Ms. Prosser accepted the challenge and CSE was organized and incorporated. Ms. Prosser teamed up with Mr. William H. Mitchell, Jr., who had previous environmental engineering experience. Mr. Mitchell is now the president of CSE, with Ms. Prosser as the Business Manager and Chief Financial Officer.

In 1993, the Massachusetts Department of Environmental Protection (DEP) restructured their oil and hazardous waste cleanup program. In an effort to reduce government oversight and speed up the remediation of contaminated sites, DEP partially privatized the cleanup program by developing the Licensed Site Professional (LSP) program. The LSP program and subsequent LSP Association has streamlined the cleanup process by allowing Licensed Site Professionals (LSPs) to conduct assessments and oversee cleanups at contaminated sites while minimizing delays associated with DEP. Mr. Mitchell was among the first in the country to obtain a full LSP designation from the Massachusetts Board of Hazardous Waste Site Cleanup Professionals. Since 1993, CSE has successfully completed hundreds of projects and has serviced a large and diverse client base.

Our Team

Clean Soils Environmental, Ltd. (CSE) is comprised of a highly qualified team of professionals including geologists, environmental scientists and field technicians specializing in a wide variety of environmental site assessments, remedial activities, permitting, and regulatory compliance. CSE believes that the success of a project depends upon fully understanding our client’s needs which is benefited by a high level of involvement by key senior personnel. This participation helps to facilitate good communication, focused efforts, and the attention to detail that our clients have come to appreciate. Our team’s flexibility and extensive consulting experience allows us to seamlessly integrate our staff with your project to quickly and efficiently to address an outstanding range of projects.

Meet Our Team

William H. Mitchell, Jr., LSP
President/LSP     Mr. Mitchell is the Co-founder and President of CSE as well as the registered Licensed Site Professional (LSP License # 1965) and Certified OSHA Hazardous Waste Site Cleanup Supervisor. In addition, Mr. Mitchell holds a Certificate of Professional Achievement in Hazardous Waste Management from Northeastern University Center for Continuing Education and maintains a full membership with the Massachusetts LSP Association. Mr. Mitchell, who earned a B.S. degree in Geological Sciences from Salem State University, has held positions in the areas of oil and hazardous waste assessments and cleanups, oil and gas exploration, geology, and geophysics in both Massachusetts and Alaska. His wide range of environmental knowledge and experience bring an interdisciplinary approach to solving environmental problems. Mr. Mitchell is one of the few LSPs that still perform field services including cleanup oversight, collection of field data, management of laboratory data, and more.

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Kevin L. McAndrews
Project Manager, Geologist     Mr. McAndrews has been with CSE since 2012 after graduating from Salem State University (SSU) with a Bachelor of Science in Geological Sciences, and was promoted to Project Manager in 2014. An aspiring Licensed Site Professional (LSP), Kevin leads the CSE team during environmental investigations and remedial projects in accordance with Massachusetts General Law c. 21E and the Massachusetts Contingency Plan (MCP). His proficiencies include project coordination, developing conceptual site models and remedial action plans, directing immediate response actions for sudden releases of oil and hazardous materials, and providing real estate due diligence services including Phase I & II Environmental Site Assessments consistent with ASTM standards. Kevin is responsible for providing clients all phases of environmental consulting from client consultation to project completion.  Also, he holds an Federal Aviation Administration (FAA) Remote Pilot Certificate with a small Unmanned Aircraft Systems (sUAS) rating, acting as the remote pilot-in-command for CSE’s drone, a DJI Mavic Air unit, for aerial surveillance during site activities.

Aerial Drone Services

CSE offers our clients Unmanned Aircraft System (UAS) or ‘drone’ services to assess site locations quickly, cost effectively, and — most importantly — safely. We are fully insured and FAA Part 107 certified. We provide our clients aerial footage for marketing, mapping, inspection and data collection. We own a DJI Mavic Air and an Autel Robotics X-Star Premium, both drones are equipped with the latest camera technology offering 4k Ultra High-Definition and wide-angle lenses to capture the highest quality video and photos possible. We are constantly leveraging technology to provide our clients with better quality information while streamlining their processes.

We recently partnered with DroneDeploy a leading drone software platform for aerial site intelligence in real time for industries including Agriculture, Construction, Roofing & Insurance, Solar Energy, Surveying, Mining & Aggregates. With this program we can provide high quality orthomosaic maps with elevation data, volumetric calculations, 3D models and agricultural NDVI surveying for all levels of site planning and assessment.

With our drone technology, CSE can help with:

  • Phase I Environmental Site Assessments
  • Aerial Inspections and Property Reconnaissance
  • Emergency Response for Hazmat Spills
  • Pre-Construction Site Planning and Design
  • Building Inspections and Roofing Insurance Claims
  • Geological Studies and Site Exploration Professional Aerial Photography Drone Pilot


John Erik Strom
Environmental Geologist     John Erik Strom is the newest member of our team and began working at CSE in September of 2019. A graduate of Salem State University (SSU), he holds a bachelor’s degree in Geological Sciences with a concentration in Marine Geology. Prior experiences include work with The National Science Foundation, The National Lacustrine Research Facility (LaCore), Salem Sound Coast Watch and the Peabody Essex Museum/Historic New England. Mr. Strom’s specific skillset includes soil sampling, sedimentary lab techniques, coring methods, use of ground penetrating radar, water quality monitoring, geophysical data collection/processing, report writing, and geologic mapping. John Erik’s work and relationships with clients and colleagues mirrors CSE’s high standards of honesty and integrity. He places great value on working together to achieve common goals in a structured and safety-minded manner.

Denise M. Prosser, MBA
Chief Financial Officer     Ms. Prosser is the Co-founder, Chief Financial Officer, and former President of CSE. Ms. Prosser holds a B.S. degree in Business Education and a Masters degree in Business Administration (M.B.A.) from New Hampshire College and has completed advanced coursework in the areas of environmental assessment and environmental law. In addition, she has studied oil and hazardous waste cleanup regulations in seminars sponsored by MassDEP. Ms. Prosser manages all the financial and operational aspects of business activities including planning and implementation of corporate growth and investment strategies.

Our Clients

At CSE, we value our clients. Our goal is that each client of CSE is so satisfied with our environmental consulting services and performance that they become a repeat client for years to come.

Our environmental solutions have provided assistance for clients ranging from due diligence assessments during real estate transactions for both buyers and lenders, to commercial development and ownership transfer, all the way to legacy property owners with inherited environmental challenges at industrial facilities.

Our Clients Include:

  • Residential Property Owners
  • Commercial Business Owners
  • Developers
  • Insurance Companies
  • Financial Institutions
  • Municipalities
  • State Agencies
  • Federal Agencies
  • Public Agencies
  • Non-Profit Organizations
  • Contractors
  • Institutions
  • Law Firms
  • Consultants

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  • Recent Posts

    “CSE has provided the Town of Ipswich with professional environmental services associated with releases of oil and hazardous materials at our DPW facility. CSE responded quickly to these releases and solved these problems according to DEP regulations and within budget.”

    - Armand Michaud, Department of Public Works – Town of Ipswich, MA

    “I would like to take this opportunity to let you know that it has been a pleasure to work with you and your staff. There was much apprehension in the community when we began removing municipal underground storage tanks. Many officials were alarmed by the time and expense this project would require. I found your genuine desire to expeditiously complete the project in a cost effective manner refreshing. It has been my experience that most consultants view municipal government as a perpetual and unlimited source of funding. I never felt that way working with Clean Soils.

    I welcome your candor and your drive to complete the task at hand. I would gladly consider your firm should we develop a need for similar services in the future.”

    - Todd H. Dresser, Environmental Engineer – Town of Burlington, MA

    “The Town recommends you and your firm, unequivocally, as a ‘world class’ environmental consultant. Not only do you have the qualifications, technical expertise and project management skills but have professionally performed to the best interests of your client consistent with state and local requirements.”

    - Larry Rittenberg, Assistant Town Administrator – Town of Burlington, MA

    “In 2010, Clean Soils Environmental, LTD. (CSE) assisted Sports Oil Corporation in finding an end point for one of our former service stations. After having other firms work on this difficult case for many years, CSE’s simple and logical solution was very much appreciated. Sports Oil Corporation is grateful for CSE’s professional assistance.”

    - Rhonda Zero, President – Sports Oil Corporation

    “Clean Soils Environmental, Ltd. (CSE) has assisted the First Ipswich Bank in evaluating complicated environmental issues surrounding real estate acquisitions in very timely and cost effective fashion. I look forward to conducting business with CSE in the future. Thanks for all your help!”

    - Lisa Brodeur, Vice President – First Ipswich Bank

    “Cura Emergency Services has worked with a number of Licensed Site Professionals with varying degrees of success, but we have always had positive experiences with Clean Soils. Clean Soils consistently works on behalf of the responsible party to achieve compliance in a reasonable, well documented, and financially responsible manner. In emergency response situations, trust in your partners is key, and we have faith that Clean Soils will deliver for our clients and represent our company in a professional and thoughtful manner.”

    - Chris Leney, Director of Operations – Cura Emergency Services