Bucket in ancient well Pace Analytical Ground Water imageToday, approximately 50% of the United States population depends on groundwater for drinking water, and groundwater is also one of our most important sources of water for irrigation. Unfortunately, groundwater is susceptible to pollutants from many sources, and pollutants like pesticides and fertilizers can find their way into groundwater supplies over time. Road salt, toxic substances from mining sites, and used motor oil also may seep into groundwater. It is also possible for untreated waste from septic tanks, toxic chemicals from underground storage tanks, and leaky landfills to contaminate groundwater.


Groundwater Questions?


Storage Tanks

Underground storage tanks (USTs) are often used to store gasoline, heating oil, and other chemicals. There are estimated to be over 4 million storage tanks buried in the United States and approximately 542,000 underground storage tanks that store petroleum or hazardous substances. If the contaminants leak into the groundwater, this contamination can affect drinking water supplies for decades. 

Septic Systems

Septic systems, onsite wastewater disposal systems used by homes, offices or other buildings that are not connected to a city sewer system, are one of the main causes of groundwater contamination in the United States. They are designed to slowly drain away human waste underground at a slow, harmless rate. Septic systems that are improperly designed or maintained can contaminate groundwater with bacteria, viruses, nitrates, and many other unpleasant contaminants.

Pesticide and Fertilizer

Pesticide and fertilizer use is widespread, and these are not only used in agriculture, but also by homeowners, cities, businesses, and even golf courses. These chemicals generally enter the environment as herbicides, insecticides, fungicides, rodenticides, and algaecides. As these chemicals accumulate on lawns and crops, they can also be transported by stormwater runoff to surface waters and eventually migrate to groundwater.


Municipal Solid Waste Landfills are designed with a protective bottom liner (clay and plastic) to prevent contaminants from leaching into the groundwater. Landfill liners are not impregnable and, as a result, groundwater monitoring programs are required by permit. Construction and Demolition (C&D) landfills frequently are not lined and contaminants such as PFAS have the potential to leach into the groundwater.   

Road Salts

The widespread use of road salt is another source of potential groundwater contamination. Road salt is used in the wintertime to melt ice on roadways to keep automobiles from sliding. When the ice melts or during rain events, the salt can be transported to surface water and eventually leach into groundwater.

Atmospheric Contaminants

Since groundwater is part of the water cycle, contaminants in other parts of the cycle, such as the atmosphere or surface water, can eventually be transported to our groundwater supplies.


  • Microbiology
  • PAHs
  • PBDE(s)
  • PCBs
  • Pesticides
  • Radiochemistry
  • SVOCs
  • Total Organic Halogens (TOX)
  • Total Petroleum Hydrocarbons
  • VOCs

The Pace® team combines the talents of experienced chemists, project managers, sampling technicians, and dedicated product and program managers, to assist in the selection and application of appropriate sampling and analytical testing strategies. This allows us to provide support on the most demanding projects. With over 60 laboratories, over 40 service centers, and 34 locations that provide groundwater sampling, Pace® provides comprehensive, nationwide service.