Improvements in the Greenbrier Watershed
Reducing Filamentous Algae Blooms
Greenbrier Watershed
The Greenbrier River Watershed is in southeastern West Virginia and encompasses approximately 1,646 square miles within Pocahontas, Greenbrier, Monroe and Summers counties.
Nestled in the heart of Greenbrier County, the Greenbrier River is a tributary of the New River, and is the longest free flowing river in West Virginia, spanning 162 miles.
The Greenbrier River is a popular fishing and recreational area for many. One of the Greenbrier's most attractive features is the Greenbrier River Trail. Formerly a railroad, the Trail offers visitors spectacular views while navigating its 78-mile stretch.
Filamentous Algae
While the Greenbrier River Watershed offers many opportunities for public recreation, such as swimming, fishing, and boating, this recreational use was interrupted by the growth of filamentous algae blooms in large portions of the Greenbrier River.
What are Filamentous Algae?
Filamentous algae are connected algae cells that grow and form long threads or filaments. When growth is excessive, large mats can form that stretch from the river bottom to the surface and cover significant portions of a river reach. Several different types of filamentous algae were present in the Greenbrier River, predominantly Cladophora and Spirogyra, but also Hydrodictyon and Oedogonium. Although the algae did not produce harmful toxins, they did create a physical impediment to recreational use of the river.
For more information about Filamentous Algae Blooms, click the button below.
Algae in the Greenbrier
During the summer of 2007, WVDEP received numerous complaints regarding the amount of algae in the Greenbrier River, mostly centered on the Caldwell to Alderson section of the river; an additional complaint was received about a location further upstream in the Denmar area.
In September 2007, WVDEP Division of Water and Waste Management held a meeting to discuss the problem and summarize the results of water quality samples from the Water Quality Standards and Assessment Section sample database. These results showed elevated levels of phosphorus in Howard Creek, which flows into the Greenbrier River at Caldwell where the algae problem was initially reported, and that phosphorus levels in Howard Creek were significantly higher below the White Sulphur Springs sewage treatment plant (WSS STP) than above the plant. Wastewater treatment plant discharges from the towns of Ronceverte and Alderson were also contributing phosphorous to the Greenbrier River, with algae growth increasing downstream of those discharges. The growth of these non-toxic algae interfered with the recreational use of the river.
As the algae decayed, drinking water supplies were often affected, resulting in taste/odor complaints with the drinking water.
2010 Algae Impairment Map
During this time, 35-50 miles of the river were significantly impacted by filamentous algae each year, with areas of major impact located downstream of sewage treatment plant discharges. As a result of seasonal algae blooms interfering with the designated uses of the river, West Virginia Department of Environmental Protection (DEP) included portions of the Greenbrier River on the 303(d) list of impaired waters in 2010.
WVDEP Study
Before progress could be made toward fixing the algae problem, a crucial question had to be answered:
Why was the algae problem so severe on the Greenbrier River, but no algae blooms present on other rivers that had wastewater discharges similar to those of White Sulphur Springs, Ronceverte, and Alderson?
WVDEP’s Water Quality Standards and Assessment Section embarked on a multi-year study of the Greenbrier and other West Virginia rivers to answer this question. Ultimately, it was determined that natural water chemistry plays a large role in the availability of nutrients discharged by the wastewater treatment facilities and used by the algae for growth. Other streams may have had higher levels of nutrients, but the phosphorous in these streams was being bound by calcium and magnesium so that the phosphorus was not available to fuel any significant algae blooms. However, the Greenbrier River had water chemistry ideally suited for growing algae, even with lower levels of nutrients than was present in other streams.
Click the button below to access the full Environment Matters: Reducing Greenbrier River Algae Story on YouTube.
Quantifying Tolerance Levels
Before towns along the Greenbrier River could be required to remove more phosphorus from their wastewater treatment plant discharges, WVDEP also had to define “how much was too much” filamentous algae. WVDEP partnered with the natural resource research firm Responsive Management to conduct a user survey to define West Virginian’s tolerance levels for filamentous algae growth. This survey asked respondents to look at pictures of various levels of algal growth and determine whether that amount of growth would interfere with their recreational use of a stream.
WVDEP's Water Quality Standards and Assessment Section used these findings to develop a standardized, objective methodology for determining if a stream's recreational use was impaired by filamentous algae.
Greenbrier River Restoration Plan
The Greenbrier River Restoration Plan was developed in 2014 as a cooperative approach between DEP and the towns of Alderson, Ronceverte, and White Sulphur Springs to bring about significant progress toward attainment of the designated uses of the Greenbrier River.
Implementing this adaptive management strategy as an alternative approach to TMDL development has focused resources where they are needed most and expedited attainment of West Virginia’s narrative water quality standards. This strategy is consistent with a United States Environmental Protection Agency (EPA) goal that States may use alternative adaptive management approaches to traditional TMDL development where such approaches are better suited to achieve water quality goals.
The Greenbrier River Restoration Plan provides a technical justification for implementing new permit limits for phosphorus in all three towns' wastewater treatment plant NPDES discharge permits. An average monthly limit of 0.5 mg/l phosphorus was incorporated into the NPDES permits, and a compliance schedule was included in the permits to provide time to construct new treatment units capable of complying with the 0.5 mg/l limit.
To access the completed Greenbrier River Restoration Plan, click the button below.
Impairment Status
When is Use Restored?
WVDEP’s 303(d) Listing Methodology for Algae Blooms specifies the protocol and growth thresholds for identifying impairment caused by filamentous algae blooms. The listing methodology was incorporated in the 2014 WV Integrated Water Quality Assessment and Monitoring Report and has been used for determining impairments related to filamentous algae since that time. The original Listing Methodology did not directly address delisting, i.e., how long and under what circumstances a stream would need to exhibit growth below the stated impairment thresholds before it would be delisted. In the Draft 2018/2020/2022 Integrated Report, WVDEP described its criteria for removing a stream from the 303(d) list.
A stream may be delisted if any of the following apply:
• WVDEP has evaluated the stream for impairments of Water Contact Recreation for a period of five consecutive years and found no blooms which would have caused the stream to be listed as impaired for recreational use.
• Specific measures to control algae growth have been implemented, and WVDEP has evaluated the stream for a period of three consecutive years finding no algae blooms causing use impairment.
• For algae impairments related to the Public Water Supply use, when taste and odor complaints associated with algae blooms are alleviated and no treatment beyond “conventional treatment” is required at the drinking water treatment facility for three consecutive years.
WVDEP’s observation and measurement of filamentous algae growth, and its monitoring of taste and odor complaints in drinking water, have resulted in the removal of portions of the Greenbrier River from the Draft 2018/2020/2022 303(d) list. One assessment unit of the Greenbrier River which remains listed for use impairment caused by filamentous algae will be evaluated using these same criteria.
Click the button below to access the 303(d) lists.
Making Improvements
Advanced nutrient removal technology was installed on three wastewater treatment plants discharging into impaired sections of the Greenbrier River after this stream was first listed for filamentous algae impairment in 2010. Following the upgrades, reductions in filamentous algae blooms occurred quickly and were commensurate with reductions in phosphorous loading from the treatment plants. WVDEP has monitored instream water quality and levels of filamentous algae growth for several years after the installation of the nutrient removal units. Monitoring occurs in late spring to early fall when flows lower and temperatures rise, as these conditions are most likely to create an algae bloom.
White Sulphur Springs
Phosphorus Treatment
White Sulphur Springs completed an upgrade of the town's wastewater treatment plant (WWTP) in October 2010. The new treatment plant utilized a vertical loop reactor (VLR) system which significantly improved the biological removal of nutrients, reducing the effluent phosphorous load by roughly 50%. The corresponding reduction in algae growth below White Sulphur Springs was strong evidence that reducing the nutrient load from wastewater treatment plants would reduce the algal growth in the river.
In 2017 a continuous flushing tertiary sand filter system and associated chemical addition equipment to remove phosphorous was implemented at White Sulphur Springs. Together the 2010 and 2017 plant upgrades remove about 90% more phosphorous than the old treatment plant did prior to 2010.
White Sulphur Springs Phosphorus Treatment Project Layout
White Sulphur Springs Treatment Facility Upgrades from the Phosphorus Treatment Project
White Sulphur Springs WWTP Phosphorus Treatment Project Upgrades
The following chart shows the Monthly Averages (mg/L) of effluent phosphorus in treated wastewater at the White Sulphur Springs Wastewater Treatment Plant from 2013 - 2019
Monthly Average of Total Phosphorus at the Town of White Sulphur Springs WWTP from 2013-2020.
Upgrades at the Ronceverte WWTP included a new Vertical Loop Reactor, Clarifiers, Tertiary Disk Filters, UV Disinfection, Sludge Digesters, and a Centrifuge.
See photos below
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Town of Alderson
The original construction of the Alderson Wastewater Treatment Plant occurred in the mid 1970s. By the mid 1980s, the second phase of the sewer system construction was completed and overflows were removed. The Alderson WWTP received a Solids Handling Upgrade in the late 1990s.
In an effort to reduce nutrient loading and algae growth in the Greenbrier River, the Alderson WWTP performed a major upgrade which was completed in 2017. The Town of Alderson installed a tertiary magnetite ballasting system, including a mixing tank, tertiary clarifier, and chemical addition equipment for phosphorous removal. In 2020, Alderson discontinued addition of magnetite and increased alum feed rates. This, along with continued use of the tertiary clarifier, has improved their effluent phosphorous concentration.
Upgrades at the Alderson WWTP included installing new headworks and a vortex grit removal system, UV disinfection, and replacing aeration equipment in the sludge holding tank.
See photos below
Flash Mix Tank (Left); Tertiary Filter (Middle); UV Disinfection (Right)
This graph summarizes data reported on the WWTP’s “Discharge Monitoring Reports”. Upgrades occurred at different time frames, and the data is not from the same years for each facility. The reported data clearly illustrates significant reductions in phosphorous loading from each facility as the upgrades became fully operational.
Approximately 12 million dollars in grant funding from the WV Legislature helped to spur upgrades at the Alderson, Ronceverte, and White Sulphur Springs wastewater treat facilities totaling more than 30 million dollars. WVDEP estimated that the new phosphorous removal technology at the WWTPs would lower their combined summertime total phosphorous loading by 83%, lowering the river’s total “algal-available phosphorous” load by 78%. Given that the Greenbrier was a phosphorus limited system, DEP predicted a corresponding approximate 80% reduction in algal growth in the river. The Table below shows that reductions in phosphorous did result in the predicted, substantial corresponding reductions in algae growth in the Greenbrier River based on observations conducted 2018-2020.
Reductions to Total Phosphorous with Corresponding Reductions in Growth of Filamentous Algae
* Load reductions compared pre-upgrade years of 2008-2010 to post-upgrade years. Post-upgrade dates vary with when individual WWTP upgrades were fully operational.
Algae Coverage Comparison Aug 2019 & 2014
To quantify the amount of filamentous algae growing in the river, WVDEP measures and maps the lateral extent of algal growth (percent of the river covered by algae, bank to bank) and performs longitudinal assessment to determine how far that level of growth extends downstream. This graph displays the level of observed algal growth in the Greenbrier River from Caldwell to Fort Spring. The graph compares the percent of the river covered by filamentous algae, before and after the wastewater treatment plant upgrades, during the peak growing season in two years with a similar amount of flow in the river. The treatment plant effluent phosphorous loadings were reduced by more than 80%, and this resulted in an 85% reduction in the measured surface acres of the river covered by filamentous algae.
Mapping the Improvements
This map shows the reduction of algae improvements since the Greenbrier River was first listed on the 303(d) list in 2010.
Click on the clock icon for an interactive experience.
Multiple investigations conducted by DEP have determined that significant progress toward restoration of use have been made by reducing phosphorus contributed by point source discharges.
WVDEP better defined its listing procedures for impairments caused by filamentous algae, resulting in the upper section of the Greenbrier above river mile 50.0, and the lower section below river mile 12.1, being delisted in 2014. Further delisting is slated to occur when the Draft 2018/2020/2022 303(d) list is approved as a result of the upgrades at the WWTPs.
Looking Ahead
WVDEP is implementing Phase 2 of the Greenbrier River Restoration plan and is working with the Town of Ronceverte to utilize the existing infrastructure at the WWTP in the most efficient manner, considering the additional steps needed during periods of very low flow in the river. The goal of Phase 2 is to further reduce the growth of algae below the town of Ronceverte and help ensure that the recreational use of the entire Greenbrier River is fully restored.
In the summer of 2023, an electrical problem at the Ronceverte WWTP impeded operation of the phosphorus removal unit. The Ronceverte WWTP is working diligently to correct the issue.
2007
WVDEP investigates complaints of large areas of algae growth reported by multiple citizens. Sampling results and observations indicate algae growth is associated with phosphorus from discharges at nearby WWTPs.
2008
WVDEP determines hardness and alkalinity levels in the Greenbrier River are ideal for maintaining dissolved phosphorus availability to fuel filamentous algae blooms.
2009
WVDEP performs major water quality study of the Greenbrier River to quantify contributions of nutrients, and subsequently includes NPDES permit requirements limiting phosphorus discharges from WWTPs to Greenbrier River; Environmental Quality Board (EQB) identifies deficiencies in DEP’s permitting strategy and remands challenged permits to the agency for action.
2011
At WVDEP's request, WV Legislature adds language to the Conditions Not Allowable in the Rules Governing West Virginia Water Quality Standards ( 47CSR2 ) prohibiting algae blooms which impair or interfere with a stream’s designated uses. The Legislature makes facilities in the Greenbrier watershed eligible for special funding for nutrient removal upgrades.
2012
WVDEP and Responsive Management complete research West Virginia Residents’ Opinions On And Tolerance Levels Of Algae In West Virginia Waters to determine level of algae growth that interferes with recreational use of a river.
2013
WVDEP’s Water Quality Standards and Assessment Section develops the Greenbrier River Restoration Plan, which includes technical rationale for phosphorus limits in NPDES permits for Ronceverte, Alderson, and White Sulphur Springs.
2014
WVDEP reissues NPDES permits for Ronceverte, Alderson, and White Sulphur Springs. Permits contain interim and final phosphorus limits and a compliance schedule allowing time for construction of new advanced nutrient removal treatment units.
2016
Floods delay phosphorus reduction projects at several WWTPs.
2017
White Sulphur Springs and Alderson WWTP Phosphorus Treatment Projects successful in lowering phosphorus concentrations; Ronceverte WWTP upgrades result in significant effluent phosphorus reductions, as well as reductions in suspended solids.
2018-2019
With advanced nutrient removal at three municipalities, algae related impairments are almost entirely eliminated.
2020-2022
The Draft 2018/2020/2022 303(d) List removes impairment for most of the Greenbrier River.
2023
EPA accepts the REVISED WVDEP WQSAS Greenbrier River Restoration. Revisions included adaptive management updates and a description of Phase 2 of the plan.
2023-2025
WVDEP will be implementing Phase 2 of the Greenbrier River Restoration Plan to move toward fully restoring use which includes, collect monthly water quality data and algae measurements at established monitoring stations during algae growing season, and performing at least one longitudinal evaluation of the impaired segment of the Greenbrier river annually near the peak of the growing season.
Photos of the Greenbrier River Comparing Algae Growth Before & After WWTP Upgrades
Greenbrier River at Fort Spring in 2008 (left); Greenbrier River at Fort Spring following WWTP upgrades at White Sulphur Springs and Ronceverte in 2019 (right).
Greenbrier River below Ronceverte at Rockland, prior to WWTP upgrade September 2016 (left); Greenbrier River below Ronceverte at Rockland, after WWTP upgrade August 2018 (right).
