Cryptosporidium is a common parasite found in the Potomac River, and it may pose a risk to your health. The main source parasites like Crypto are old calves and adult cattle in the area.
City Water
Washington D.C. Water Quality Analysis
8 min read
- 01 | Who Regulates Washington D.C.’s Water Supply?
- 02 | DC Water’s Annual Water Quality Report
- 03 | Environmental Working Group Water Quality Report
- 04 | Where Does Washington D.C. Get Its Water?
- 05 | Treating the District of Columbia’s Drinking Water
- 06 | Health Risks of Washington D.C.’s Treatment Process
- 07 | Testing and Monitoring Washington D.C.’s Drinking Water
- 08 | Contaminants Threatening Washington D.C.’s Water Supply
- 09 | Keeping Lead Out of Washington D.C.’s Tap Water
- 10 | Why Does Washington DC’s Water Have Such a Strong Chlorine Smell In the Spring?
- 11 | What Can You Do to Protect Your Tap Water?
- 12 | Should D.C. Residents Use In-Home Water Filters?
Washington D.C. is command-central for the nation, but does it have its own tap water under control?
All things considered, they do an okay job of making their water safe to drink.
The real issue, though, is that they’re an old city with a lot of old lead pipes, and they’ve found some pretty high levels in recent years.
Then of course there’s the taste…
D.C. uses a large amount of chlorine and chloramines, and that stuff stinks!
It’s time to learn the hard facts about the District of Columbia’s drinking water.
Without further ado...
Several organizations work together to oversee Washington D.C.’s water supply, including:
- The Environmental Protection Agency (EPA) sets national treatment standards for contaminants in public water systems.
- The Food and Drug Administration (FDA) regulates bottled water production.
- The Washington Aqueduct and the U.S. Army Corps of Engineers treats the district’s drinking water.
- DC Water is in charge of testing, monitoring and distributing the city’s tap water.
Here’s what DC Water found in their latest water quality report:
DC Water’s Annual Water Quality Report determines whether or not the city passes federal and state water standards.
In their most recent report, Washington D.C. met or exceeded all of the EPA’s safety requirements.
With that said, the results were far from perfect…
Although D.C.'s water is consistently below the EPA’s bacteria limits, they did find trace amounts of Giardia and Cryptosporidium in at least 12 source water samples.
When it comes to lead exposure, nearly 10% of private homes contain some level of lead.
Legally, at least 90 percent of the city’s samples must be below the EPA’s limits. They passed, but they barely squeaked by.
Most of the lead was found in low-income areas where old service lines are more common.
Considering the city’s long history of lead poisoning, this is an ongoing concern.
The Environmental Working Group (EWG) is a non-profit organization that publishes independent water quality reports.
Overall, their standards are much stricter than the EPA’s.
According to them, the EPA’s regulations don’t take into account the latest research on drinking water pollutants and their side effects.
That’s not too surprising, though, considering they haven’t been updated in over 20 years!
In the EWG’s latest report, they found 12 cancer-causing contaminants above healthy limits, including:
- Arsenic: 34x EWG HEALTH GUIDELINES
- Bromochloroacetic acid: 196x EWG HEALTH GUIDELINES
- Bromodichloromethane: 194x EWG HEALTH GUIDELINES
- Chloroform: 64x EWG HEALTH GUIDELINES
- Hexavalent chromium: 4.3x EWG HEALTH GUIDELINES
- Dibromoacetic acid: 8.5x EWG HEALTH GUIDELINES
- Dibromochloromethane: 32x EWG HEALTH GUIDELINES
- Dichloroacetic acid: 63x EWG HEALTH GUIDELINES
- Haloacetic acids: 267x EWG HEALTH GUIDELINES
- Nitrate: 9.1x EWG HEALTH GUIDELINES
- Total trihalomethanes: 269x EWG HEALTH GUIDELINES
- Trichloroacetic acid: 121x EWG HEALTH GUIDELINES
That’s a whole lot of carcinogenic compounds!
So which report should you listen to... DC Water’s or the EWG’s?
At the end of the day, it’s up to you to decide which guidelines to follow.
If you want to play it safe, you can install a home water filter and remove up to 99.9% of harmful contaminants (you just have to pick the right one, but more on that later).
For now, let’s take a closer look at where the nation’s capital gets its tap water:
Washington D.C. gets its drinking water from the Potomac River.
The city withdraws 140 million gallons of water a day for the city’s 700,000 residents.
On its way to your house, the water travels through 1,350 miles of water mains.
First, though, it’s filtered and treated with chemical disinfectants and fluoride.
Here’s a quick overview of the treatment process in action:
The Washington Aqueduct (Aqueduct) treats D.C.’s drinking water at the Dalecarlia and McMillan treatment plants.
Their multi-step treatment process turns raw water from the Potomac river into safe drinking water.
Here’s a what the process looks like in a nutshell:
- Screens trap large debris as the raw water enters the treatment plant.
- Pre-sedimentation allows large particles to settle naturally at the bottom of the tank.
- Coagulation and flocculation add chemicals so small particles stick together and can be easily removed.
- Sedimentation removes large particles from the bottom of the tanks.
- Filtration uses hard coal and gravel gravity filters to remove small particles.
- Fluoridation adds fluoride to protect teeth from cavities.
- Lime and caustic soda are added to adjust pH.
- Orthophosphate is added to prevent corrosion in pipes.
- Chlorine is added to kill harmful organisms before water leaves the plant.
- Ammonia is added to create chloramine.
- Chloramine provides ongoing disinfection as the water travels through distribution pipes to your home.
The Potomac River isn’t necessarily the cleanest body of water in the world, which is why D.C. has to treat it so heavily.
Unfortunately, the treatment process comes with a few downsides…
Chlorine and chloramines create harmful contaminants called disinfection byproducts (DBPs).
Early research shows that DBPs may increase the risk of birth defects and bladder cancer.
Yikes!
Unfortunately, DBPs are a necessary evil because chemical disinfection is the only way to effectively kill pathogens in large volumes of water.
Fluoride is another controversial compound…
Studies show that long-term exposure can cause skeletal fluorosis, a bone disease with symptoms like ligament calcification and joint pain.
There is light at the end of the tunnel, though…
In-home water filters can remove chlorine, chloramines, DBPs and fluoride!
Next up, we’ll take a quick look at how the District of Columbia monitors your drinking water:
How does the city know that the treatment process actually works?
They test, test and test some more!
Each year, DC Water takes over 6,500 samples and performs more than 40,000 water quality tests (this is far more than the EPA requires).
In addition to testing for the EPA’s regulated substances, DC water also tests for unregulated compounds to watch for new threats.
They also have a watershed protection program to monitor the effects of agriculture and industry on the Potomac River and nearby bodies of water.
Despite their best efforts, some contaminants manage to sneak through...
As D.C.’s water flows through rivers, lakes and streams, it picks up contaminants.
This is a serious problem across the country, but because of D.C.’s dense population it’s especially challenging.
Some of the main contaminants to lookout for are:
- Pesticides and herbicides from stormwater runoff, agriculture and residential uses
- Radioactive materials from rocks and soil or mining and oil and gas production
- Organic chemicals from petroleum production, gas stations, septic systems, stormwater runoff and industrial processes
- Inorganic contaminants from wastewater, mining, farming, stormwater runoff, or oil and gas production
- Microbial contaminants, like viruses, bacteria and parasites from septic systems, sewage treatment plants, wildlife and livestock
You might not notice the side effects right away, but these substances can wreak havoc on your health.
Pregnant women, young children, the elderly, cancer patients and people with immune system disorders are the most at risk.
If this sounds like you, ask a healthcare professional for advice about your drinking water.
Chances are, they’ll recommend getting a high-quality water filter for your home.
But even if you don’t have extra health risks, you still have to worry about D.C.’s most dangerous contaminant: LEAD.
The District of Columbia first discovered lead in their drinking water in 2001.
All of the sudden, they were faced with widespread lead poisoning that left thousands of children with lifelong health risks.
Just how bad was it?
That year, lead levels were 83 times higher than the EPA’s safe limit!
Lead is a toxic heavy metal that can cause health problems like cancer, birth defects, learning disorders and heart disease.
It enters the water through corroded lead pipes, which are common in old household plumbing and service lines throughout the city.
In 2001, part of the problem was the city’s high use of chloramines, which corroded old lead pipes at an alarming rate.
Since then, they started using less chloramines, but corrosion control and lead exposure is still an ongoing issue.
In addition to cutting back on chloramines, the city now adds orthophosphate to prevent pipe corrosion.
At the same time, thay have an extensive program to replace lead service lines.
Qualified residents receive grants to cover the costs of private service line replacements, depending on household size and income.
The city is also hard at work identifying and replacing all publicly owned lead service lines, but there’s a lot to be done.
Most of the year, D.C. uses chloramine to disinfect the water after it leaves the treatment plant.
But for a short time each spring, they switch from chloramine to using only chlorine.
Chlorine is a stronger disinfectant and it helps kill the extra bacteria that forms in lakes and rivers this time of year.
The problem is that all that chlorine stinks, not to mention the extra DBPs it produces!
Next, let’s take a closer look at what you can do to protect your tap:
- Run your water for two to three minutes if it’s been sitting for several hours. When your water sits for long periods of time, it degrades.
- Use only cold water for drinking and cooking. The water in hot water heaters usually has higher levels of metals, sediment and bacteria.
- Have your water professionally tested for contaminants at least once a year.
- Identify and replace old lead service lines and household plumbing components.
- Clean faucet screens (aerators) at least once every three months. Contaminants can build up and leach into your drinking water.
- Regularly replace water filter cartridges in your home water filter.
The District of Columbia has its hands full when it comes to providing clean drinking water.
At best, your water will contain fluoride, chlorine, chloramine and toxic DBPs. At worst, it will contain lead.
Activated charcoal pitchers and faucet filters can improve the smell and taste, but you’ll have to pull out the big guns if you want to keep your family safe.
Reverse osmosis (RO) systems can remove up to 99.9% of all harmful contaminants.
They combine sediment filters, activated carbon filters, ion exchange resins, RO membranes and polishing filters to remove chlorine, chloramines, DBPs, bacteria and lead.
Cloud Water Filters even use built-in software to track water usage and ship replacement cartridges right to your door.
You’ll never have to worry about clean water again!
Click here to learn more.
