Karst's are above or underground caverns, usually made of limestone or calcium carbonate, that over time tend to collect water and create aquifers. When such aquifers are found near residential areas, they make ideal sources of water as the water is assumed to be pure and the supply often endless. However recent studies show that this may be a serious misjudgment as human contamination transported by groundwater runoff is increasingly having an impact on these once pristine sources of drinking water. Without continued proactive karst conservation legislation, many of these delicate ecosystems will eventually be destroyed and lost forever.

Across every continent, except Antarctica, are found above ground and underground caverns. When water dissolves this very soluble rock, the result is a cavern, a waterfall, a lake, a sinkhole, or any number of topographical changes. This is referred to as karst topography.

Recent testing of some karst aquifers have revealed groundwater contamination. Groundwater flows into the underground through conduits allowing little opportunity for filtration or sorption of contaminants before reaching the karst. Reports of karst contamination is appearing more frequently in the news and sometimes resulting in the need to abandon the use of these karst springs and aquifers as a source of drinking water entirely. Some recently impacted regions in the US have been Kentucky, Virginia, and just this past May, Tennessee.

Basin type draining tends to collect anything and everything off the surface of the land and this can leave the water unfit for human use as fecal contamination containing e coli bacteria, pesticides, herbicides, and chemicals used by industry can sometimes find their way into these aquifers. The best way to protect a karst aquifer from pollution is to practice karst conservation, requiring humans to limit industry and other polluting activities over the groundwater basin.

In the meantime, there are new risks that we face from karst drinking water. First, individuals coming across a karst in nature may assume that the clear water is safe to drink. This is becoming less and less the case. The other concern is for those who have relied on a karst for decades to supply them with water. A karst aquifer can provide pure drinking water for 100 years, but can become contaminated very quickly once exposed to chemicals or contaminants.

As the population grows and pollution continues, the risks of contamination also increase, and thus routine testing of these karst aquifers should become a mandatory requirement. Fortunately, there are some glimmers of hope as citizens begin to better understand the sensitivity of these essential ecosystems and endorse karst conservation. Just this month, in British Colombia, karst conservation legislation was introduced to do just that.

Do not assume a clear pool in a natural setting is automatically sanitary. If you are hiking, it is best to take your own water along, even if you will be a long way from any sign of life. Another option is to take along a portable water filter such as the sport berkey that will remove bacteria and contaminants.

If your primary daily water source is from a Karst, a recommended precaution is to filter it prior to ingestion. Even if the water has been tested and deemed safe for drinking in the past, an unknown contamination could occur quickly and put your family's health at risk. Berkey water filters are one way to accomplish this. They are able to filter out bacterial contamination and other chemicals to undetectable levels while also leaving in the important beneficial minerals that karst aquifer's regularly possess.