Groundwater Treatment & Contaminants

What is Groundwater Treatment

Treatment of site water to remove pollutants to meet water quality requirements before discharge.

Identifying Groundwater Contaminants

Environmental and geotechnical reports are the primary source of information. Reports may not include water quality data for nuisance contaminants that could interfere.

Phase 1 Environmental Assessment

  1. Identifies potential contamination sources
  2. User questionnaires & visual observations
  3. Regulatory records view

Phase 2 Environmental Study

  1. Presents site evaluation process & results
  2. Soil boring logs/Soil sample analysis
  3. Water quality analysis

Common Contaminants

Below are contaminants that require treatment prior to discharge. Identifying contaminants that aren’t regulated in discharge permits is essential because of their impact on system performance & filtration media:

  1. Total Suspended Solids
  2. pH
  3. VOCs/SVOCs
  4. Arsenic, Other heavy metals
  6. Turbidity
  7. Hydrogen Sulfide
  8. Radium, Radon, Uranium

Not Regulated but Impacts Treatment

  1. Iron
  2. Competing Ions
  3. Manganese

Treatment & Filtration System Components

D.Blog groundwater 3 blog post

Settling Tank

  1. Settles solids with or without oxidation
  2. Requires space
  3. Least expensive method to remove heavier solids


Involves the injection of sodium hypochlorite in mixer prior to settling tank to convert dissolved elements to solids.


Injection of sequestering agents to keep undesirable minerals in suspension and prevent them from oxidizing during the treatment process.

Dewatering Bag & Filter

Filtration removes contaminants that can be oxidized easily or that do not settle out in the Settling Tank, such as suspended solids, iron, and other pollutants.

Adsorption Vessels

D.Blog groundwater 4 blog post

  1. Series of vessels with media beds that target site-specific pollutants
  2. Simple Process
  3. Quantity of media based on contact time & duration

Discharge Permits

Permitting depends on local, state, and federal regulations. Water quality requirements vary based on the discharge point. Project permits will define water quality level that needs to be met.