State of Our Rivers - Swim Guide E. Coli Report for 2023
This Swim Guide Report provides an interim E. coli pollution analysis for the year between our biannual State of Our River reports. In this edition, we look back at E. coli testing results from popular recreation sites throughout our mountain region, collected from Memorial Day through Labor Day weekends in 2023.
2023 Region-wide Analysis
MountainTrue works to protect and restore the waterways of the Southern Blue Ridge Mountains as healthy aquatic ecosystems that are great places to swim, paddle, and play.
We are the home of the Broad Riverkeeper, French Broad Riverkeeper, Green Riverkeeper, Watauga Riverkeeper, and Western Clean Water Team — the primary guardians of their respective river basins. Our Swim Guide program is powered by our volunteers, who help monitor pollution, and our members and supporters, who help fund this crucial work.
In 2023, MountainTrue staff and volunteers collected, processed, and analyzed 1,307 water samples from 94 Swim Guide sites on the following waterways:
- Broad River
- Elk River
- French Broad River
- Green River
- Hiwassee River
- Little Tennessee River
- Nantahala River
- New River
- Nottely River
- Pigeon River
- Watauga River
- Valley River
How We Measured
The State of North Carolina currently doesn’t have a surface water quality standard. However, in 2022, the NC Department of Health and Human Services recommended a threshold of 126 MPN/100 mL for primary recreation activities such as swimming and snorkeling, where people are more likely to submerge their heads and inadvertently consume water. For secondary recreation activities with less direct contact with the water, such as kayaking, tubing, and fishing, the department recommends a threshold of 886 MPN/100 mL.
MountainTrue collects and analyzes water samples using the EPA-approved IDEXX method. Results are expressed as the Most Probable Number (MPN) of E. coli cfu (colony-forming units) per 100 ml of water.
- Green dots - passed for primary recreation (sites with a mean below 126 MPN/100 mL)
- Yellow dots - passed for secondary recreation (sites with a mean between 126 and 866 MPN/100 mL)
- Red dots - failed both primary and secondary recreation levels. (sites above 866 MPN/100 mL)
Region-wide E. coli mean: 475.2 MPN/100 mL
Region-wide E. coli mean, excluding the French Broad River: 230.9 MPN/100 mL
The region-wide mean E. coli level for the 2023 Swim Guide Season was 475.2 MPN/100 mL, which is well above the primary recreation standard but below the standard for secondary recreational activities. However, this mean is significantly skewed by the higher E. coli levels of the French Broad River, which carries the brunt of human impacts in the region due to higher population density, increased development, aging infrastructure, poor agricultural practices, and a changing climate.
If you exclude the French Broad River, the mean is 230.9 MPN/100 mL. This stark difference highlights both the overall good quality of most of the rivers in our area and the drastic need to take corrective action in the French Broad Water.
2023 by the Numbers
94
Swim Guide sites tested
1,307
Water samples analyzed
61
Volunteers who helped us
30
Swim Guide Sponsors
French Broad River Basin
The French Broad River continues to suffer from higher levels of bacteria pollution, but there are some signs of progress. In a 2023 statewide comparison of Swim Guide data among other North Carolina Riverkeepers, the French Broad remains the worst, and many of our most popular sites still routinely fail to meet either the primary or the secondary recreation standards.
The French Broad River continues to suffer from higher levels of bacteria pollution, but there are some signs of progress. In a 2023 statewide comparison of Swim Guide data among other North Carolina Riverkeepers, the French Broad remains the worst, and many of our most popular sites still routinely fail to meet either the primary or the secondary recreation standards.
- Lower French Broad River - mean E. coli: 251.0
- Middle French Broad River - mean E. coli: 1015.8
- Upper French Broad River - mean E. coli: 1390.0
- Pigeon River - mean E. coli: 280.9
The mean E. coli level for the French Broad and Pigeon rivers was 893.1MPN/100mL, which is just above the secondary recreation standard of 886 MPN/100 mL. However, the middle and upper sections of the French Broad River were significantly more polluted than the Lower French Broad River (251 MPN/100 mL) or the Pigeon River (280.9 MPN/100 mL) which more often than not met the safety threshold for secondary recreation.
Our cleanest sites in 2023 were recreation areas further from significant development or where the river traveled through protected areas of Pisgah-Nantahala National Forest or Great Smoky Mountain National Park, such as:
- Pigeon River at Hartford, 30.0 MPN/100mL
- Pigeon River at Creasy Cove, 33.7 MPN/100mL
- French Broad River at Hot Springs, 114.0 MPN/100mL
- French Broad River at Stackhouse, 142.9 MPN/100mL
- French Broad River at Ledges Whitewater Park, 201.0 MPN/100mL
Our most commonly failed sites were primarily along the Middle and Upper French Broad River and its tributaries. These sites are in or near urban areas with higher development and failing wastewater infrastructure, such as:
- [Unnamed Tributary] at Shiloh, 1884.9 MPN/100mL
- French Broad River at Hap Simpson, 1820.8 MPN/100mL
- Cane Creek at Fletcher Community Park, 1754.3 MPN/100mL
- Hominy Creek near Bear Creek Rd, 1601.5 MPN/100mL
- French Broad at Westfeldt Park, 1581.7 MPN/100mL
The French Broad River at Westfeldt Park and Cane Creek at Fletcher Park failed every sample we took in 2023, and Hominy Creek at the Greenway failed over 93% of the time. Despite the failures, we are seeing some improvements, particularly at sites in Buncombe and Madison counties. Our sites at Bent Creek, Asheville River Arts District, Pearson Bridge, Woodfin, and Hot Springs all improved from last year's samples.
The Swim Guide helps us monitor and track down pollution hot spots. In 2023, we finally tracked down a sewer leak at one of our worst Swim Guide sites, Shiloh. The E. coli levels at that site have improved dramatically and the $2 million investment we secured to prevent runoff pollution from agriculture should also help the river continue to improve.
If you would like to sponsor a site along the French Broad or Pigeon River, please contact hartwell@mountaintrue.org.
2023 by the Numbers
38
Swim Guide sites tested
474
Water samples analyzed
30
Volunteers who helped us
2
Swim Guide Sponsors
Broad & Green River Basins
The Broad River Basin includes the main stem of the Broad River and its tributaries, including the Green, First Broad, Second Broad, and North Pacolet rivers. In 2023, the combined mean E. coli level for the Broad and Green rivers was 169.0 MPN/100mL, which is a little above the primary recreation standard of 126 MPN/100mL but still well below the 886 mpn/100mL threshold for secondary recreational activities. 2022 data showed the mean at 160 MPN/100mL, so the numbers are slightly up, but the Southern Region of MountainTrue’s watersheds continues to have some of the lowest average levels of bacteria.
Green Riverkeeper
The Green River continues to be one of the cleanest watersheds each Swim Guide season thankfully in large part due to the 14,000+ acres of the protected Green River Game Lands, which is public land protected from development. However, after heavy rains, we have seen site failures which we attribute to sediment and erosion runoff.
- Green River - mean E. coli, 281.8 MPN/100mL
The mean E. coli level was 281.8 MPN/100mL, which is above the primary recreation standard of 126 MPN/100 mL but still well below the threshold for secondary recreation. This number represents 11 weeks of data compared to the 15 weeks we normally test due to a lack of numerical data in the first 4 weeks of sampling. *For the first four weeks of the 2023 sampling season, every site passed the 126 MPN/100ML level, except one site. The first week, we just didn’t get the numerical data other than pass/fail!
Our cleanest sites in 2023 were the Upper Green Put-in access which is right below Tuxedo Dam and Bradley Falls which is also protected by the Green River Game Lands and protected from development.
- Upper Green Put-in Access, 113.6 MPN/100mL
- Bradley Falls, 282.4 MPN/100mL
In 2023, our most commonly failed sites were Big Rock Access which is protected on one side by the Green River Game Lands, but adjacent to that is private property and some development on the other side of the river. Big Hungry River also has some protections from the Green River Gamelands, but we have seen significant sediment and erosion run-off issues from upstream in the past.
- Big Rock Access, 362.4 MPN/100mL
- Big Hungry River, 318.2 MPN/100mL
If you would like to sponsor a site along the Green River, please contact erica@mountaintrue.org.
Broad Riverkeeper
The Broad River watershed on average continues to have some of the lowest levels of bacterial contamination. These numbers are somewhat skewed by the very low levels of E.coli in both Lake Lure and Moss Lake. Bacteria levels in the main stem of the Broad River were slightly lower than in the First Broad River.
- Broad River - mean E. coli, 118.8 MPN/100mL
The Broad River watershed average E.coli of just 118.8 MPN/100mL is below both the primary recreation standard of 126 MPN/100 mL therefore usually safe for swimming, and the 886 mpn/100mL threshold for secondary recreational activities such as boating and fishing. In 2023 MountainTrue asked the Water Resources Division of NC Department of Environmental Quality to consider reclassification of a section of the Broad River that is frequently used for swimming and is shown to have low levels of bacteria pollution. Reclassifying from C-secondary recreation to B-primary recreation would be a more appropriate designation and offer better protection of the waterway.
Waters in highly developed areas or with intensive animal agriculture tend to have higher levels of bacteria. Our lakes and rivers in forested areas have cleaner waters.
Our cleanest sites in 2023 were recreation areas on Moss Lake and Lake Lure. Years of data collection show that streams that feed lakes usually have higher bacteria than the lakes themselves. Bacteria entering the lake is effectively attenuated by dilution and settling.
- Moss Lake at Camp Creek Ch Rd picnic area, 12.3 MPN/100mL
- Lake Lure Swimming Beach at the Inn, 35.8 MPN/100mL
In 2023, our most commonly failed sites were the First Broad River below Lawndale and the Coxe Road access on the Broad in Rutherford County. Both of these sites are in areas with a lot of agriculture and inadequate riparian buffers.
- Broad River @ Coxe Rd, 193.5 MPN/100mL
- First Broad @ Double Shoals, 172.0 MPN/100mL
If you would like to sponsor a site along the Broad Green River, please contact david@mountaintrue.org.
2023 by the Numbers
16
Swim Guide sites tested
238
Water samples analyzed
6
Volunteers who helped us
10
Swim Guide Sponsors
Hiwassee and Little Tennessee River Basins
The Hiwassee Watershed continues to be one of the cleanest watersheds for the 2023 Swim Guide season. However, we continue to see problems in the Valley River, due to a lack of riparian buffers and impacts from animal agricultural operations.
In 2023, MountainTrue’s Western Region Clean Water Team collected 310 samples from 21 Swim Guide sites from Memorial Day to Labor Day with the help of five volunteers. The mean E. coli level across all sites was 278.0 MPN/100mL in both the Hiwassee and Little Tennessee River basins. Of the watersheds the Western Region Clean Water Team samples, the Nantahala and Nottely River watersheds were the cleanest overall, followed by the Hiwassee River, which includes Lake Chatuge and Hiwassee. Sites that failed the most were in the Little Tennessee near Franklin and the Valley River watersheds near Murphy and Andrews.
- Hiwassee mean E. coli: 219.7
- Nottely mean E. coli: 92.9
- Valley mean E. coli: 517.5
- Little Tennessee mean E. coli: 474.8
- Nantahala mean E. coli: 13.2
In 2023, MountainTrue’s Western Region Clean Water Team collected 310 samples from 21 Swim Guide sites from Memorial Day to Labor Day with the help of five volunteers. The mean E. coli level across all sites was 278.0 MPN/100mL in both the Hiwassee and Little Tennessee River basins. Of the watersheds the Western Region Clean Water Team samples, the Nantahala and Nottely River watersheds were the cleanest overall, followed by the Hiwassee River, which includes Lake Chatuge and Hiwassee. Sites that failed the most were in the Little Tennessee near Franklin and the Valley River watersheds near Murphy and Andrews.
The median of 15 sites in the Hiwassee River basin was 272.4, including the Valley River watershed (averaging 517.5) and the Nottely (averaging 92.9). In 2022, the average E. coli level in the Hiwassee was 207.2 MPN/100mL. The majority of this 31% increase between 2022 and 2023 was due to the addition of the Hiwassee River at the Hiwassee Street site, which failed every test. Both the Nottely and Valley River averages improved over the 2022 levels.
The average of six sites sampled by MountainTrue in the Little Tennessee River basin was 323.8 MPN/100mL, but that average was brought up by two really clean sites on Fontana Lake at the Fingerlake Day Use Area (averaging only 4.06 MPN/100mL) and the Nantahala River (averaging 22.4 MPN/100mL. Three of the top five sites with the most failed tests were on the Little Tennessee River near Franklin.
Cleanest Sites
Our 8 lake sites, including Chatuge, Fontana, Hiwassee, and Nottely, were the cleanest locations averaging less than 20 MPN/100mL. Other really clean sites were the Nantahala River at Ferebee Memorial Picnic Area (averaging 22.4 MPN/100mL and Fires Creek at the USFS Picnic Area (averaging 27.1 MPN/100mL).
- Lake Nottely at Poteete Creek Swim Beach, 1.8 MPN/100 mL
- Fontana Fingerlake Day Use Area, 4.1 MPN/100 mL
- Hiwassee Lake at Hanging Dog, 5.0 MPN/100 mL
- Lake Chatuge at USFS Jackrabbit Swim Beach, 8.4 MPN/100 mL
- Lake Chatuge at Clay Co. Rec Park Swim Beach*, 13.9 MPN/100 mL
*While on average for the whole summer, Lake Chatuge at Clay Co. Rec Park Swim Beach was one of the cleanest sites, this location does often have a problem with goose poop during the month of August.
Most Failed Sites:
Sites that failed the most are in or downstream of developed areas or in areas of more intensive animal agriculture like:
- Hiwassee River at Hiwassee St, 1156.4 MPN/100 mL
- Little Tennessee at Lake Emory Canoe Launch, 699.8 MPN/100 mL
- Valley River at Konehete Park (Murphy), 681.2 MPN/100 mL
- Little Tennessee at Tassee Launch Area, 602.2 MPN/100 mL
- Little Tennessee at Sanderstown Rd, 541.0 MPN/100 mL
The Hiwassee River at Hiwassee St. failed all 15 tests and averaged an alarming 1,156.4 MPN/100mL. This is due almost entirely to domesticated populations of Canada goose and domestic ducks that congregate at the site to be fed by humans.
If you would like to sponsor a Swim Guide site in the Hiwassee and Little Tennessee River Basins, please contact callie@mountaintrue.org.
2023 by the Numbers
21
Swim Guide sites tested
310
Water samples analyzed
5
Volunteers who helped us
3
Swim Guide Sponsors
Watauga, Elk, and New River Basins
In 2023, the three watersheds that MountainTrue’s Watauga Riverkeeper covers (Watauga, Elk, and New) had similar averages, but the Watauga had the lowest levels of E. coli overall.
- Elk River - mean E. coli: 223.4 MPN/100mL, 15 samples
- New River - mean E. coli: 232.3 MPN/100mL, 104 samples
Watauga River - mean E. coli: 222.4 MPN/100mL, 166 samples
The mean E. coli level was 226.1 MPN/100mL, which is above the primary recreation standard of 126 MPN/100 mL but still well below the threshold for secondary recreation. This represents a minor overall decrease in E. coli levels from 2022 to 2023. In 2024, we added 5 more additional sites in the New River watershed.
Our cleanest sites in 2023 were recreation areas on lakes, or in locations that were upstream from significant development, such as:
- Watauga Point, 11.3 MPN/100mL
- Wilbur Dam, 20.3 MPN/100mL
- Shook Branch, 38.6 MPN/100mL
- Price Lake, 68.1 MPN/100mL
- Payne Branch Park, 115.7 MPN/100mL
Our most commonly failed sites were primarily in or downstream of urban areas with higher development, failing wastewater infrastructure, or are impacted by activities along the stream bank (dog poop, bird poop, etc.), such as:
- Lovers Lane, 626.5 MPN/100mL
- Blevins Boat Ramp, 567.8 MPN/100mL
- Hunter Bridge, 320 MPN/100mL
- Boone Greenway, 422.6 MPN/100mL
- Brookshire Park, 310 MPN/100mL
If you would like to sponsor a site, please contact andy@mountaintrue.org.
Thank You To Our Swim Guide Sponsors
MountainTrue, our riverkeepers, and our entire Clean Water Team would like to thank our 2023 Swim Guide site sponsors, volunteers, and donors, without whom this work would not be possible.
Broad Riverkeeper site sponsors: Shelby Women for Progress, Rutherford Outdoor Coalition, Joy Pharr Realty, and Fabbit Customs
French Broad Riverkeeper site sponsors: Pink Mercury and Pirani
Green Riverkeeper site sponsors: Wilderness Cove Campground, The Purple Onion, The S.P.O.T., Green River Cove Tubing, Lake Adger Property Owners Association, and Hendersonville Community Co-Op
MountainTrue West site sponsors: Union County (GA) government, Towns County (GA) government, and the City of Hiawassee, GA
Watauga Riverkeeper site sponsors: Asheville Fly Fishing Company, Appalachian Veterinary Ultrasound, Mellow Mushroom of Boone, Explore Boone, Boone Cocoon, Tennessee Valley Authority, Animal Hospital of Boone, Birdies Coffee, The Speckled Trout Outfitters, Rivergirl, Zach Hobbs, Boone’s Fly Shop, Trophy Water Guide Service, and Blue Ridge Tourist Court
2023 by the Numbers
21
Swim Guide sites tested
285
Water samples analyzed
20
Volunteers who helped us
15
Swim Guide Sponsors