The Life Cycle of a Water Sample

On a sunny day in June, David Huffman walks to a flowing stream in downtown Raleigh to show off the process for collecting a routine water sample. 

He lugs a bucket full of scientific equipment across a grassy field and down an embankment, but the first part of the process does not require any of those tools. That’s because the first step is to take a moment to stop, observe and appreciate his surroundings. 

One of the perks of this job, according to him, is traveling to different monitoring sites and enjoying the scenery and wildlife. 

“We encourage our water monitors to take a minute and enjoy the natural beauty of North Carolina,” Huffman said. 

As the coordinator for the Ambient Monitoring System (AMS), Huffman manages water quality sample collection at more than 300 sites around the state. These samples are taken to a lab and analyzed to provide data to help track water quality across North Carolina.

David Huffman stands in Prairie Creek and collects a water sample.

Along with its sister program, the Random Ambient Monitoring Systems (RAMS), AMS is maintained by the Water Sciences Section of the Division of Water Resources (DWR) at NCDEQ. These vital programs help provide long-term data and trends for tracking the quality of North Carolina’s waters. 

“We have the largest surface water monitoring network in North Carolina,” Huffman said. “We have over 300 stations covering all 17 major river basins.”

What are the AMS and RAMS programs?

DWR has multiple programs to monitor the quality of streams, rivers, lakes and estuaries across North Carolina. These programs follow standards and operating procedures to ensure data consistency and quality – and to ensure they are scientifically sound and defensible. 

Huffman carries water sampling materials while walking through the Prairie Creek Ecostation.

There is a program through the DWR Biological Assessment Branch to monitor aquatic life, including invertebrates and fish, that live in all river basins across the state. Another program, Ambient Lakes Monitoring, tracks the water quality of approximately 160 lakes of more than 10 acres in size that are used for water supply or recreation. Data is collected for a subset of lakes each year, so that they reach all 160 lakes every five years.

The AMS program has more than 300 stations that have measured physical, chemical and biological parameters for up to 60 years. At each AMS station, the measures of water quality, or parameters, are collected monthly to create a background on the water quality conditions of sites at the stations.

For the RAMS program, DWR staff randomly select up to 30 different freshwater sites for monitoring. To select these sites, program staff drop random points on a GIS map of all streams in the state, contained in a dataset from the United States Geological Survey (USGS). 

Two plastic bottles containing water samples collected by Huffman. They are sitting on ice in a cooler ready to be sent to a lab.

By dropping points randomly on streams around the state, each freshwater site has an equal chance to be chosen. The randomization of the selection of monitoring sites allows the RAMS program to fulfill an U.S. Environmental Protection Agency’s (EPA) Clean Water Act (CWA) requirement of being representative of all freshwaters in the state. The program began in 2007, and since then, these locations change every two years. 

“We can’t monitor every single point on every single stream all the time, but by randomly selecting sites, DWR has a statistically valid sample that the division can use to make statements about the quality of freshwater streams across the state,” said Tammy Hill, supervisor of the DWR Water Sciences Ecosystems Branch.

The RAMS program collects parameters covered by the AMS program as well as pesticides, mercury, metals and volatile organic compounds. Staff can monitor up to 250 different parameters at sites in the RAMS program, Hill said.

“The data collected by the RAMS program fill in gaps from the AMS program and allow staff and researchers to find early indicators of potential issues,” Huffman said.  

At the Stream to the Lab: The Life Cycle of a Water Sample Begins

The life cycle of a water sample in the AMS and RAMS program begins in the stream itself. At a stream at the Prairie Ridge Ecostation in Raleigh, Huffman lugs his equipment down to the stream. 

Huffman carries water sampling materials while walking through the Prairie Creek Ecostation.

Huffman must capture a stream sample to test it for certain parameters. The parameters measured generally include a measure of microscopic organisms that can indicate the presence of fecal matter, turbidity - a measure of the clarity of the water -, as well as nutrients such as nitrogen and phosphorus, dissolved oxygen, pH, conductivity and temperature. 

Huffman pulls out several plastic bottles, which he labels according to each parameter being tested. One by one, he dips the bottles into the stream and fills them up.  

When collecting a sample, it is key that the bottle is filled as much as possible to ensure a high-quality result, Huffman said.

After collecting the samples, he places them on ice in a cooler, so they can be transported to a lab. A sheet of paper is assigned to every collection with a barcode that tells the lab which bottle holds the parameter measured.

Huffman places the meter under water for about a minute. Using an app on his cell phone, he collects data from the meter in real time.

Huffman shows the data he collects with the meter on his cell phone.

Once the lab receives the data, it is analyzed and put into a database. This information is then accessible for others to view and provides a snapshot of what is happening in the water at the site.

While it can take a significant amount of time for staff to drive out to the sampling sites around the state, the collection of the water sample itself takes relatively little time, Huffman said. But overall, the review of the data is the hardest part of the process.

“Once the data is produced,” Huffman says, “it takes the most amount of time to make sure it is of quality, defensible and accessible to the public.”

How to Access the Water Quality Data Online

According to Huffman, the easiest way to access this data is to go through How’s My Waterway, a website maintained by the EPA.

The general public can search by location to find data collected by the AMS and RAMS programs, as well as other programs.

The dataset organizes the reported data by parameter, and the website highlights topics designed for the public to explore including swimming, aquatic life and drinking water.

What is the Overall Importance of the AMS/RAMS Program?

The AMS and RAMS programs are key tools to aid in the protection of the quality of North Carolina’s waterways.

"These programs provide the vast majority of the data used for water quality assessment by the state for surface waters,” Hill said. “The process of assessing the quality of waters of the state is a requirement under the Clean Water Act, and that responsibility is delegated for us to do that work. The data are used to compare water quality measures to state standards, and ultimately used to determine if a water body is impaired or not, along with other programs that aim to track down the source of problems, and develop management strategies to improve or address those.”

For example, the samples provide data to make decisions about basin planning, and for monitoring other programs.

Ultimately, water samples help the division protect North Carolina’s water quality for wildlife and people.