Water Quality Monitoring

With the passing of the Clean Water Act in 1972 water quality monitoring has become a staple for rivers and streams across the country. Unfortunately, over 70% of our national waterways still remain unassessed. While the Anacostia is currently monitored by local, state, and federal agencies in some capacity, Anacostia water quality data still remains difficult to find or is absent for some locations. Water quality is essential to ensuring residents have safe and healthy access to the river and its streams for recreation like fishing, boating, and paddling.

The ARK Water Quality Monitoring Program

We aim to provide up-to-date, accurate water quality data for the Anacostia to not only ensure the health of its waters, but to provide recreators with the information they need to enjoy the Anacostia in a fun and safe environment.

Our water quality program is built on community science. We recruit volunteers each year to help us collect samples and investigate our waterways to track their health. In 2019 we started one of the first volunteer-based community water science programs in the District of Columbia; and in 2020 established a similar program in the Maryland portions of the watershed.

In total we’ve established 20 water quality stations across the watershed with sites in the District of Columbia, Montgomery County, and Prince George’s County. 

Two volunteers with a water-testing kit and clipboard taking water samples at the edge of a creek that flows to the Anacostia River.

Become a monitor!

DC Training Sessions

Read our most recent reports

Anacostia Riverkeeper’s priority is to share data as widely as possible with our community. In addition to weekly results throughout the summer, we compile reports for our water quality monitoring programs at the end of each year. Click below to read our most recent reports to learn about the current state of the Anacostia’s water quality. Please share them with your community and ask us any questions about our results.

Current Anacostia Conditions

Below are the most recent bacteria water quality results for each of our monitoring programs. You can use the interactive map and zoom into each site to find full data for all water quality parameters. We recommend avoiding contact with the water for 72 hours after a major rain event.

“Collecting consistent water quality data throughout our watershed is a critical first step to a “swimmable Anacostia”. Even though we aren’t fully swimmable yet, this data can inform many other recreation decisions we make in our watershed too. For example, I always check the water quality data before putting my kayak in the water!”

– Petra Baldwin

Water Quality Coordinator

District of Columbia Water Quality

Swimming has been illegal in DC waters since the 1970s, an issue preventing District residents and visitors from fully enjoying their local rivers and streams. However, due to capital investment in both green and grey infrastructure, current water quality trends show that portions of the Anacostia would be safe for swimming during certain periods throughout the year.

The push towards water quality transparency in the District

We’re a part of a multi-organization effort, funded by the District Department of Energy and Environment (DOEE) and implemented by the Alliance for the Chesapeake Bay, to recruit and train volunteers throughout the District.

Our volunteer team collects water quality samples at 24 sites from May to September each year. As the Anacostia Riverkeeper, we’re in charge of nine (9) sites along the mainstem Anacostia with our partners Rock Creek Conservancy, Nature Forward, and Alliance for the Chesapeake Bay, monitoring sites in the Rock Creek and Potomac River. Through this monitoring program we hope to address the negative stigma surrounding Anacostia water quality and show District residents and visitors that Anacostia river health is improving and that recreation on the Anacostia can be both fun AND safe.

We post water quality results for bacteria (E. coli), turbidity, pH, water temperature, and air temperature weekly in order to provide up-to-date water quality information for residents and visitors to DC during the recreational season (May to September). We aim to get water quality information into the hands of the people who need it most: YOU!

Current DC Anacostia Water Quality Sites

Project Funders

Logo of the DC Dept of Energy and Environment
The Washington, DC government logo with the tag line "We are DC"

Maryland Water Quality

Our water quality monitoring programs in MD use citizen scientist volunteers to collect water quality samples in the mainstem Anacostia as well as in the at-risk tributaries in the watershed from May to September each year.

Our monitoring started in 2020 with funding from the National Fish and Wildlife Foundation (NFWF) covering 7 sites across MD and DC. In 2023 we expanded to 10 sites in Maryland. Five sites are located in Montgomery County and monitoring is funded by the Chesapeake Bay Trust and the Montgomery County Water Protection program, with the other 5 sites located in Prince Georges County and funded by the Chesapeake Bay Trust. To help us in Montgomery County we’ve teamed up with Friends of Sligo Creek and Neighbors of Northwest Branch to help us train our volunteers, spread the word, and help our volunteers collect samples. In Prince George’s County we’ve built a partnership with Friends of Quincy Run, Friends of Lower Beaverdam Creek, Sustainable Hyattsville, and the Stream Team at Joe’s Movement Emporium. 

We post water quality results for six parameters: bacteria, dissolved oxygen (DO), turbidity, pH, water temperature, and air temperature biweekly in order to provide up-to-date water quality information for residents and visitors to the Anacostia watershed during the recreational season (May to September). We aim to get water quality information into the hands of the people who need it most: YOU

Current MD Anacostia Water Quality Sites

Project Funders

A graphic in the style of a Maryland license plate, featuring a graphic of the Bay Bridge and a crab against blue water and sky, with the words "CB Trust" in the center.

Become a monitor

Read our reports

Access our datasets

Anacostia Riverkeeper Water Quality Data Request Form

Anacostia Riverkeeper has been collecting water quality data throughout the watershed since 2018. Currently, our dataset encompasses recreational water quality for the Anacostia in the District of Columbia from 2019 to 2023 and recreational as well as ecological data from Maryland tributaries from 2020 to 2023. Our data is publicly accessible on Chesapeake Monitoring Cooperative and available upon request and agreement with our Data Use Agreement. Please submit your request and we will respond within a few days.

What is fecal bacteria?

Fecal bacteria are bacteria like E. coli and Enterococcus that live in the guts of warm-blooded animals and enter our waterways via sewage, runoff, and pet waste. Our water quality monitoring programs analyze the Anacostia mainstem and its tributaries for E. coli as an indicator of the presence of more dangerous bacteria that can cause illness.

The primary sources of fecal bacteria in the Anacostia are combined stormwater, sewage overflows (CSOs), and pet waste swept into the river during storms. However bacteria can come into our waterways via illegal dumping and leaking pipes among other ways.

How do we measure fecal bacteria?

We analyze our samples using the IDEXX Colilert system which allows us to sample and report E. coli levels all within a 24-hour window. Fecal bacteria is the primary water quality parameter used to asses the recreation potential of waters and is one of the parameters used in “recreational contact standards”. While swimming is currently banned in DC portions of the watershed, collecting bacteria data is still vital to provide information to those recreating in and around the Anacostia in other ways like boating and fishing.

What is pH?

pH is the measure of how acidic or alkaline (basic) something is. It is measured on a scale from 0-14 with 0 being the most acidic and 14 being the most basic. Perfectly balanced or “neutral” water has a pH of 7.

Most waters around the Anacostia watershed range from a pH of 6.5 to 8. This is important to measure as some organisms can be stressed by water that has a pH that is to high or to low. pH also affects whether or not a waterbody passes what officials call “recreational contact standards” (6.5 to 8 in DC and MD). Many things in our watershed can affect the pH of our waterways like excess rain, illegal dumping and other pollution, and stormwater runoff.

How do we measure pH?

We measure pH one of two ways. One way is with pH strips like you would see at a swimming pool. These strips are a low cost, effective way for community scientists to collect water quality data from many different locations relatively quickly. The second way is with a multi-parameter water quality probe, which are typically more expensive. Anacostia Riverkeeper staff currently deploy water quality probes to obtain detailed pH measurements from select sites along the Anacostia in MD and DC.

What is turbidity?

Turbidity is basically a measure of water clarity, or how much light can pass through the water. Turbidity levels can vary depending on where you are geographically as well as seasonally in certain waters. Most of the mainstem Anacostia is known as a coastal plain river, meaning that it can often have a high amount of biological material or sediments in it. Lower turbidity levels are better for our local water quality as it allows more sunlight to reach bottom dwelling plants like submerged aquatic vegetation (SAV) as well as indicating less particulate matter in the water which could be a sign of pollution.

How do we measure turbidity?

Turbidity can be measured in several different ways. For our water quality program we first collect a water sample in the field and then measure turbidity in the lab. In the lab Riverkeeper staff use a turbidimeter to measure the turbidity in collected samples. Essentially shinning a light through the sample and measuring how much can pass through the sample. Our programs measure turbidity in NTUs, where normal turbidity levels in Anacostia waters would be from 0 NTU (perfectly clear) up to 20 or 30 NTU (upper limit of “normal” for our waters). Anything above 30 NTU often indicates cloudier abnormal water, possibly due to a large rainstorm or a sudden influx of sediment or another pollutant.

What is dissolved

Dissolved oxygen is a measure of the total amount of dissolved oxygen in a given waterbody. Essentially, it is the amount of usable oxygen in a waterbody that’s available to living organisms. Dissolved oxygen is a powerful indicator of overall water quality as it can be a direct measurement for how much life a waterway can support. Anacostia dissolved oxygen health typically adheres to the following:

0-2 mg/L = not enough to sustain life

2-4 mg/L = stressed conditions, only a few organisms can survive.

4-7 mg/L = quality conditions for most organisms

7-11 mg/L = great conditions for sustaining aquatic life


How do we measure dissolved

For our water quality programs we use a digital multi-parameter water quality probe with a dissolved oxygen sensor installed. This allows us to measure the amount of dissolved oxygen in our waterways in percent oxygen (DO%) as well as mg/L (DO mg/L).

What is temperature?

For our water quality program we measure both water and air temperature. Water temperature is a vital parameter to track as large fluctuations can stress wildlife as well as provide prime conditions for dangerous organisms that could impact humans. In addition to water temperature we also measure air temperature, a base parameter with direct impacts on water temperature that fluctuates seasonally. 

How do we measure temperature?

We measure water/air temperature with simple field thermometers as well as a water quality probe. For our community science programs, volunteers use certified field thermometers recorded to the nearest degree (°C). Anacostia Riverkeeper staff also use water quality probes at select sites along the mainstem Anacostia and select tributaries to obtain detailed water temperature measurements on the surface and throughout the water column.

What is conductivity?

Conductivity is a measure of the concentration of dissolved ions in a waterbody, affecting how well an electrical charge can be conducted through that water sample. In heavily urbanized watersheds like the Anacostia, these ions can come in the form of salts, the result of runoff from roads and pavement carrying road salt into the streams and rivers. High conductivity levels can affect organisms living in our rivers and streams and can be especially harmful to fish who require a delicate balance of salts in the water to live.

How do we measure conductivity?

Conductivity is measured with a conductivity sensor that is attached to a multi-parameter water quality probe. This allows Riverkeeper staff to measure conductivity quickly and efficiently from any of our monitoring sites, or to explore a new site if pollution is suspected.