More than half of the people living in the United States get their drinking water from local groundwater supplies. According to the United States Geological Survey (USGS) , groundwater should look clean and clear because that’s the way Mother Nature cleans it; she filters out particulate matter as water flows through the ground.
Unfortunately, it isn’t a 100 percent foolproof system.
Contaminants that get into groundwater can be from natural or man-made sources. Natural sources could be the introduction of dissolved iron or manganese as the water filters through the ground. Or the source of contamination may be something we humans did or are doing.
Some examples of man-made contaminants that find their way into our groundwater supplies:
· Gasoline, oil and road salts washed from our streets and roads into the soil
· Pesticides and fertilizers runoff during irrigation and rain to soak into the water supply
· Toxic substances from mining sites or hydraulic fracturing
· Untreated wastewater from septic tanks or improper treatment facilities
· Toxic chemicals that leak from underground storage tanks and landfill sites
If you don’t know it’s broken, you won’t know to fix it. This bit of conventional wisdom is applicable to clean drinking water.
If you aren’t monitoring your water supply system, you won’t know if there’s a problem brewing. It is far more cost-effective to protect water sources against contamination than clean it up after the problem is already manifesting in the population.
Safe drinking water is a critical resource. If we’ve learned anything from the water supply crisis in Flint, Michigan , it is precisely how critical clean drinking water is.
When contaminants have found their way into our water systems, it is a problem that needs a quick, reliable solution. There are different methods for treating groundwater that can remove harmful substances. These methods fall into three general categories: biological, chemical, and physical.
Biological groundwater rehabilitation methods use organics, such as microorganisms, organic matter, and (in some cases) plants to clean contaminated water. Biological filtration is an affordable water treatment plant system that relies on natural bacteria in the water. These bacteria convert and remove contaminants from the water in this easy-to-use, natural rehab method that requires little power usage.
Bioaugmentation , bioventing, and biosparging all use biological material to breakdown industrial wastewater and chemicals that may be present.
Using a chemical method for groundwater rehabilitation can take longer and may be more costly than other methods. Chemical rehab is useful on some materials, however, that other methods cannot treat. Many of the average 16,000 chemical spills occurring in the U.S. every year can pose a serious threat to groundwater sources. Using chemicals to clean up chemical contaminants is one way to fight this problem.
Some examples of chemical rehabilitation methods are carbon absorption , chemical precipitation , ion exchange, and oxidation .
Treatment methods that fall under this umbrella are usually the most basic of the groundwater rehabilitation methods. One example is air sparging, or using air to strip water clean.
The most common physical method is pump and treat. This technique does exactly what its name says: physically removing water from the ground and treating it with biological or chemical means.
Each of the categories of groundwater treatment methods has more specific ways to go about accomplishing the ultimate goal: clean water. Regardless of the technique used for rehabilitation of a groundwater source, most treatment methods result in the removal of 85-95 percent of the pollution from wastewater and other contaminants. That’s an impressive track record any day.