Soil & Groundwater Remediation in Portland, OR

Did you know that more than half of the U.S. population depends on groundwater for drinking water? This includes people served by public water systems, as well as those who get their drinking water from a private source, such as a well. 

When groundwater and soil become contaminated, it poses health risks not only for people who might rely on the groundwater as a source of drinking water. It can also be hazardous to wildlife, livestock and even pets. Contaminated drinking water can also affect plants, including crops intended for consumption by people and livestock.

While there are numerous causes of soil and groundwater contamination, several widespread activities are responsible for the majority of contaminated soil and groundwater:

  • Manufacturing
  • Local waste disposal
  • Land development 
  • Industrial dumping  
  • Heating oil tanks 

If a Phase 2 environmental site assessment (ESA) reveals the presence of hazardous materials or contamination, then additional investigation, as well as soil and groundwater remediation, may be necessary to resolve the issue. A geophysical survey can help locate buried tanks and other sources of contamination.

Groundwater Remediation Methods

Various methods are available for cleaning up contaminated groundwater. Which method is used depends on the type of contamination. 

Physical Remediation

There are two basic types of physical groundwater remediation: air sparging, and a method known as “pump and treat.” 

  • Air sparging is used to treat groundwater contaminated by volatile organic compounds, or VOCs. This involves drilling an injection well into the contaminated water table and then injecting pressurized air through the well. The pressurized air causes the hydrocarbons in the VOC to dissolve into vapor. The vapor percolates up through the water and is channeled into an extraction system to remove the contaminants. The clean air is then released into the atmosphere.
  • pump and treat system is used when dissolved chemicals, such as industrial solvents, metals and fuel oil, have contaminated the groundwater. In this case, the groundwater is pumped from one or more wells up into an above-ground treatment system to remove the contaminant(s). This type of system can also be used to prevent contaminated water from spreading.

Biological Remediation

Environmental factors, cost and the type of pollutant can influence which type of biological remediation is deemed most appropriate.

  • With bioaugmentation, naturally occurring, adapted microorganisms (bacteria and fungi) are added to treatment systems to aid in the biological degradation of contaminants such as ammonia.
  • Bioventing involves drilling one or more injection wells into the contaminated area and then pumping air through the well(s) into an unsaturated zone. The air provides oxygen to enhance the growth of existing microorganisms that can aerobically degrade compounds that are contaminating the groundwater. Nutrients and heat can be added to the bioventing process to speed it up.
  • Biosparging is used to remove contaminants such as mineral oil or aromatic compounds like benzene. Aerobic bacteria are added to the contaminated groundwater to break down the pollutants. For deeper, anaerobic layers of groundwater, injection filters are used to furnish oxygen to the bacteria. 

Chemical Remediation

Similar to biological remediation methods, the choice of chemical remediation processes depends on various factors such as cost and the type of contaminant present.

  • Carbon capture is a method of groundwater remediation in which activated carbon is injected into the contaminated area. The carbon captures and sequesters carbon dioxide and is then transported to a deep underground storage reservoir.
  • Ion exchange is often used to remediate groundwater contaminated by toxic metals. With this method, the ionic contaminant is removed from the groundwater by exchanging it with another ionic substance. The process is similar to that used for water “softening.”
  • With chemical precipitation, counter-ions are used to reduce the solubility of ionic contaminants, changing them into solid particles that can be more easily removed. 
  • Chemical oxidation involves injecting or mechanically mixing oxidants into the area to be treated. Electrons from the oxidizing reagent are transferred to the contaminant, converting it to a less hazardous, stable or inert compound. 

Soil Remediation Methods

Some of the same methods used in groundwater remediation can be used for soil remediation, also referred to as “soil washing.” And just like groundwater remediation, the method selected to remove pollutants from the soil depends on the particular situation that needs to be addressed. 

Thermal Remediation

With this type of decontamination, the soil is subjected to high temperatures to evaporate the contaminants. Typically, a conveyor belt is used to feed the soil into an oven chamber, where it is baked. The materials that are extracted are captured, cooled and disposed of, and the soil is tested to ensure that it can be safely recycled. 


With encapsulation, rather than filtering the contaminant(s) from the soil, the contaminated soil is mixed with a substance such as lime, cement or concrete to prevent the contaminants from spreading to surrounding soil or groundwater. 

Air Sparging

The process is similar to that used to treat groundwater contamination. Large volumes of pressurized air are injected into the contaminated soil to remove VOCs. This method of treating soil contamination is commonly used when carbon filtering systems cannot be used.  


As with bioremediation for groundwater contamination, this process involves the introduction of adapted aerobic and anaerobic bacteria into contaminated soil. The bacteria consume the contaminants, breaking them down into nonhazardous components. 

Your Portland, OR groundwater and soil remediation expert

If you have a situation that may require soil or groundwater remediation, call Alpha Environmental. We can assess the soil and groundwater in question and implement any remediation processes that may be needed. 

We’ll help you explore the options available to resolve your unique set of circumstances and help you decide which is the best choice.

Contact Us

A trusted member of our team will reach out within 1 business day to schedule

Why Choose Alpha Environmental

Our goal is to get the job done right while protecting our client. We are committed to ensuring you are safe in your residence, no matter what. We are fully licensed, bonded, insured, and here to help with all of your environmental needs.

Family Owned & Operated

We pride ourselves on strong company values that translate into service levels which go above and beyond average service providers

21+ Years Experience

For over two decades we've been doing the dirty work, serving residential and commercial customers in the greater Portland area

Care & Ownership

Our entire team is committed to ensuring your home or place of business is safe and every job gets done the right way

David D.
Lake Oswego, OR
Read More
My wife and I experienced a hot water pipe busting in the crawlspace. It has been a total nightmare. However, Chris and his team provided expert quality care, with timeliness and the greatest degree of professionalism. I would HIGHLY recommend Alpha Enviornmental!
Zhanna S.
Beaverton, OR
Read More
Can’t say enough about Alpha Environmental! Their costumer service is 10/10, they have really good systems in place, responsive, and professional. The gals in the scheduling department are always so kind! As a real estate agent, I use Alpha’s services numerous times a year. Either it’s for Mold bids, oil tank decommissioning, radon etc. They always do a fantastic job! Thank you for all the work you do!
Kristen L.
Portland, OR
Read More
Wow where do I even begin?? We’re absolutely thrilled by the work Alpha has done for us and we’re eternally grateful to them for ridding our house of asbestos tile! They’re polite, kind, professional — from estimator Filo to manager Dame to Jake, Melvin and the other two guys on the crew (so sorry we didn’t get your names) — you guys are awesome and we so appreciate your help. Our house looks amazing. The peace of mind you’ve given us is priceless. We can’t thank you enough. We’ll certainly be in back in touch if we ever need any of your services again. Thank you thank you!!!
Jeff S.
Salem, OR
Read More
Alpha environmental's employees were punctual, pleasant to work with and there services are reasonably priced. I highly recommend them because I would use them again in the future.
Lea C.
Tualatin, OR
Read More
Took a water sample in for lead testing and they were so fast and helpful. Rodolfo was so nice and informative in explaining the testing and what it meant! Would definitely recommend everyone to go there and will go to them for any future needs!
Claire B.
Portland, OR
Read More
Alpha environmental was extremely helpful in navigating me through the process of testing some leftover construction debris for asbestos so I could take it to the dump. Their office manager spent time with me on the phone discussing the options for sample collection, and was extremely friendly in answering my many questions. Sample drop off at the office was easy and the results even came back a few days earlier than expected. Will definitely return if I need more sampling done!
Jeff C.
Tigard, OR
Read More
I would highly recommend anyone wanting, quick efficient services relating to environmental testing to check out Alpha Environmental. Not only was the staff friendly and responsive, but also professional! If I could 6 stars out of 5, I would!
Jotham P.
Portland, OR
Read More
We used Alpha Environmental Services to conduct our home inspection, radon testing, sewer scope and oil tank decommissioning. Every part of their service was really professional. They took so many great photos of the house during the inspection and offered lots of explanation on what they found. Great team. Highly recommend!

Contact Us

A trusted member of our team will reach out within 1 business day to schedule