A Day Of Visibility For Water
On this World Water Day, learn more the basics of groundwater, which is necessary for drinking water, sanitation, our food supply, & natural world.
Here’s a riddle for you…
What always runs, yet doesn't walk, often murmurs but doesn't talk. Has a bed, but doesn't sleep, has a mouth but never eats.
Today is World Water Day, and did you know that almost all of the liquid freshwater in the world is groundwater? This precious resource supports drinking water supplies, sanitation systems, farming, industry, and ecosystems. In many places, human activities over-use and pollute groundwater. In other places, we simply don’t know how much water is down there.
About 50 percent of people in the U.S. alone depend on groundwater for their drinking water supply. Yet most people don’t know the basics about this resource.
What is groundwater?
Groundwater is water found underground in aquifers, which are geological formations of rocks, sands, and gravels that can hold water. This water bubbles up naturally through a spring or can be discharged into lakes or streams. Even though it’s underground, when it does rise up, groundwater helps to replenish and maintain levels of surface water, which are the bodies of water we can see such as rivers, lakes, streams. Groundwater helps keep our rivers flowing.
Why should we care about groundwater?
More than 70 percent of the earth’s surface is covered in water, and while that might sound like a lot, about 96 percent of it is saline—or saltwater found in the ocean. Less than 1 percent of the water on our planet is drinkable. We drink from two main sources: (1) surface water such as creeks, rivers, lakes, and wetlands, and (2) groundwater, which is water found under the earth’s surface. All this water must be treated before we drink it.
In many areas, groundwater is over-used when more water is abstracted from aquifers than is recharged by rain and snow. Groundwater pollution is a HUGE problem that impacts this water source and can take decades or even centuries to recover from. In some places, we do not know how much groundwater lies beneath our feet, which means we could be failing to harness a potentially vital water resource.
Exploring, protecting and sustainably using groundwater will be central to surviving and adapting to climate change and meeting the needs of a growing population.
How do we regulate groundwater?
We recently discussed the Clean Water Act, here in the U.S., and that law does not directly address groundwater contamination, so the government created another law called the Safe Drinking Water Act (SDWA) in 1974. It specifically covers waters designed for drinking use, including aboveground and underground sources. This law governs our tap water and makes the EPA responsible for setting safety standards for what we drink. It also requires all owners or operators of public water systems to comply with these standards.
The SDWA gives the EPA authority to identify contaminants and regulate their levels in drinking water to protect public health. The agency sets regulatory limits for more than 90 contaminants.
The EPA has three criteria, according to the law, when determining what to regulate:
a contaminant may have an adverse health effect on people
a contaminant is known to occur or there is a high chance that the contaminant will occur in public water systems often enough and at levels of public health concern
regulation of the contaminant will result in a meaningful opportunity for health risk reductions for people served by public water systems
If the EPA establishes a regulation for a contaminant, then public water systems need to comply with it. But if the EPA decides not to regulate a contaminant, then it may issue a health advisory, which is a non-enforceable federal limit that serves as technical guidance for federal, state, and local officials.
Let’s take a moment to get clear: we have enforceable and non- enforceable regulations.
Of the enforceable regulations, we have what are called maximum contaminant levels (MCLs). An MCL is the legal threshold limit on the amount of a substance allowed in public water systems according to the SDWA. The limit is usually expressed in a concentration of milligrams or micrograms per liter of water. These standards are set by the EPA for our drinking water quality.
In order to set an MCL, the EPA first looks at what levels of a contaminant can be present with no adverse health issues. That level is called the maximum contaminant level goal, which is a non-enforceable goal. The MCL is set as close as possible to the goal, but this system is not perfect.
Sometimes, the EPA will establish a treatment technique (TT) instead of an MCL, which is a procedure that must be followed to treat water for a contaminant. It’s enforceable and it’s not a perfect regulation. Both MCLs and TTs are known as primary standards in EPA-speak.
The EPA sets standards based on the science available. Maybe they know studies are coming out soon saying that a contaminant could cause cancer, so they set a goal or a health advisory, not an MCL. In other cases, they may have animal studies but not human ones. They can’t set standards when they don’t know the full impact. They can’t create regulations without enough data. It’s a slow dance of completing the studies we need to create the right rules and regulations.
For too many communities, that dance is waaay too slow.
So many people and communities across the world are fighting for clean water now. On this World Water Day, let’s send them all our support.
Other articles we’re reading this week…
State Unveils Long-Awaited Standard For Drinking Water Contaminant by Rachel Becker
In A World On Fire, Stop Burning Things by Bill McKibben
Warmer, Drier Springs To Bring Worsening Drought to U.S., NOAA Report Predicts by Cristen Hemingway James
Share your thoughts on World Water Day in the comments below. How has groundwater impacted your community?