Is There Pharmaceutical Runoff in Drinking Water?

It's a commonly asked question. With a bit of a complex answer. Is there really pharmaceutical runoff in drinking water? The answer is, most likely, yes. However traces are usually very minimal.

What do we mean by pharmaceuticals?

Pharmaceuticals contain either synthetic or natural chemicals. And they're found in prescription medicines, over-the-counter therapeutic drugs and veterinary drugs.
Pharmaceuticals consist of active ingredients designed to have health benefits.
As a result, strict regulatory processes govern these chemicals. Including rigorous testing to assess their efficacy and safety before going to market.
Because of these processes, pharmaceuticals tend to be better characterized than other contaminants.

How does pharmaceutical runoff enter household water?

Pharmaceutical runoff enters usually enters drinking water in one of three ways. Including improper disposal, incomplete metabolization or as a result of concentrated animal feeding operations.

Improper Disposal

The most likely cause of pharmaceutical chemicals entering your drinking water is improper disposal of medicine. Flushing medicine down the toilet sends these into the water supply.
And this is not exclusive to human medicine. Animals often require larger doses of pharmaceuticals, usually prescribed by veterinarians.
When owners or vets dispose of these improperly, larger amounts of chemicals enter the water supply.

Incomplete Metabolization

Sometimes remnants from medicine enter water supplies through human waste. Because not all people can metabolize all medicines.
Non-digested chemicals or hormones are therefore excreted and disposed of through the sewage system.

Concentrated Animal Feeding Operations - CAFOs

Concentrated Animal Feeding Operations (CAFOs) are also known as 'factory farms'. Farms around the country use growth hormones, steroids and antibiotics to treat their animals.
Certain animals, like humans, only metabolize a certain percentage of the chemicals or hormones they consume.
Spills from manure-storage lagoons or fertilization with manure therefore contribute to pharmaceutical runoff.

Disposal at Healthcare Facilities

Similar to the improper disposal already discussed, healthcare facilities specifically contribute to pharmaceutical water pollution.
Hospitals typically have on-site pharmacies with arrangements in place to return unused drugs to manufacturers for credit or disposal.
However, nursing homes flush medications down the toilet or drain after a patient leaves the facility. Because they typically don't have the same kind of return arrangements as hospitals.
Plus, the rules for getting rid of opioid painkillers make disposal down the drain an acceptable option. Which has encouraged some nursing homes to dispose of all their leftover medications that way.
pharmaceutical runoff in drinking water

How common is it really?

A recent AP investigation found that antibiotics, anticonvulsants, mood stabilizers and hormone medications exist in the drinking water supplies of at least 41 million Americans.
And in the last decade, traces of pharmaceuticals appeared in all phases of the water cycle. Including surface water, wastewater or groundwater. Plus drinking water.
Regardless of occurrence, this is important to consider. Because the water in your home ultimately comes from one of two places - groundwater or surface water.
Groundwater sources include various types of wells. And surface-water sources include rivers, lakes and reservoirs.

How do we monitor for these chemicals?

No single group, agency or corporation is responsible for monitoring drinking water quality. Which includes the monitoring for pharmaceuticals in drinking water.
As a result, many different organizations work together to monitor public water supplies. And for private wells, homeowners are responsible.

Why monitor?

Monitoring drinking water is important for our health and safety. The United States and Canada have some of the safest water supplies in the world. But they may still contain contaminants.
The Environmental Protection Agency (EPA) sets standards for over 90 contaminants in drinking water. Pharmaceuticals are not one of these yet. But the EPA does classify them as a contaminant of emerging concern (CECs).

Municipal Water Monitoring

The EPA regulates municipal water supplies across the country. So it sets standards that suppliers have to meet. This includes contaminant limits and water-testing schedules and methods.
Each state is responsible for implementing their own water quality standards. Since Congress voted on the Safe Drinking Water Act (SDWA) in 1974.
In addition, local water suppliers are required to test for the SDWA once every year. And every public water supplier is required to provide an annual report to its community.

Private Well Monitoring

According to the The Centers for Disease Control and Prevention (CDC), over 15 million United States households rely on private wells. Because these are not public wells, the Safe Drinking Water Act does not regulate them.
But owning a private well doesn't mean you shouldn't get your water checked annually. Or that you're on your own. Your local Culligan water expert is equipped to collect a water sample and send it to our EPA certified lab for analysis.

Is pharmaceutical runoff in drinking water harmful?

Pharmaceutical concentrations reported in U.S. drinking water have only been seen in the parts per trillion range. But recent studies have shown adverse effects for aquatic life. Which can be cause for concern.
One study specifically showed that estrogen and other similar chemicals have a feminizing effect on male fish. Which can alter female-to-male ratios. Sources of estrogen include birth control pills and postmenopausal hormone treatments.
Other research has discovered popular antidepressant medications in the brain tissue of fish downstream from wastewater treatment plants.
As a result of these studies on wildlife, scientists have begun testing for effects specific to human health.
Current observations suggest that it is unlikely for the reported levels of pharmaceuticals in drinking water to be harmful to our health. But we need to complete more research on the topic.

Is there a way for us to reduce these drinking water contaminants?

Let's say there is pharmaceutical runoff present in your drinking water. How can you treat it?
The highest removal rates of pharmaceutical runoff in drinking water come from two methods - reverse osmosis and ozonation.

Reverse Osmosis

The key to understanding reverse osmosis is first understanding the process of osmosis.
We define osmosis as the passage of a solvent, such as water, from a lower-concentration solution to a higher-concentration solution.
A semipermeable membrane separating the two solutions allows the solvent to pass. But not the dissolved particles it contains.
The flow finally stops when both solutions become equal in concentration. We classify this process as passive transport. Because no energy needs to be applied.
So what is reverse osmosis then?
Unlike osmosis, reverse osmosis requires an external force to complete the transport. Therefore, pressure is a key part of the reverse osmosis process.
And like its name implies, reverse osmosis is the opposite of osmosis. Because instead of balancing out the two solutions, the external force of pressure reverses the natural flow.
Since contaminant molecules are larger than water molecules, only water pushes through the semipermeable membrane. Applying more pressure to the contaminated water makes the reverse osmosis process more effective.


Ozonation is the process of water filtration without the use of harsh chemicals like chlorine. It is used to disinfect water supplies and control odor. Plus, it reduces contaminants.
So how exactly does ozonation work?
First, electrolytic and chemical reactions create energy. These are also known as ozone generators.
Dry, clean air then passes through a high voltage electric discharge. Which creates an ozone concentration.
Next, water passes through a tube which creates a vacuum. And the vacuum pulls the ozone gas into the water. The air bubbles up through the water, treating the water as it passes through.

How much do reverse osmosis and ozonation remove?

Pharmaceuticals in water respond to treatment no differently than organic chemicals. So removal rates depend on their unique properties and the chosen treatment method.
Conventional water treatment processes reduce pharmaceutical runoff by about 50 percent. While more advanced treatment processes, like ozonation, activated carbon filters and reverse osmosis, achieve even higher removal rates.
For example, reverse osmosis reduces these chemicals by more than 99 percent.

Are there specific Culligan solutions for pharmaceutical runoff?

At Culligan, we have the experience and the technology to treat pharmaceutical runoff in your drinking water. We therefore offer a wide variety of products, solutions and services.
And each solution is customizable to suit the needs of your home. Available products include water softeners, reverse osmosis systems, whole house water filters, water filtration systems and bottle-free water coolers.
So what are you waiting for? Call your local water expert today and start customizing a water solution plan for your home and family.