January 6, 2020. On December 23, 2019, the UNC Policy Collaboratory released a legislatively mandated report on nutrient pollution in Jordan Lake.  The short version: A three year, multi-million dollar study has confirmed the science and policy underlying the 2009 Jordan Lake water quality rules.

Background.  In 2002, the North Carolina Environmental Management Commission (EMC) designated Jordan Lake as having impaired water quality due to excess nutrients  (nitrogen and phosphorus) contributing to algal blooms in the lake. The EMC and  water quality staff  in the Department of Environmental Quality (DEQ) spent seven years developing a nutrient management strategy to address water quality standard violations in Jordan Lake as required by the federal Clean Water Act and by state water quality  laws.   In 2009, the EMC adopted rules to implement the final nutrient management strategy.  Following guidelines in state law, the rules required all major nutrient sources — wastewater treatment plants, agricultural operations,  runoff from new development activity and previously developed areas  — to take steps to reduce nutrient releases to the lake.  The 2009 nutrient management strategy set goals for nitrogen and phosphorus reduction to be met by a combination of wastewater treatment plant upgrades, agricultural best management practices and stormwater controls including riparian buffers along rivers and streams.

Later in 2009,  the legislature adopted the first of.a series of acts revising or delaying implementation of the Jordan Lake nutrient rules in response to complaints from  local governments and  real estate development interests.  Communities in the Haw River watershed, including Burlington and Greensboro,  voiced particularly strong objections to the rules. In 2013,  legislators directed the water quality program to test an unproven in-lake technology to reduce algal growth as a possible substitute for nutrient reduction rules and appropriated $1.35 million to support the pilot project. (See an earlier post about the “Solar Bee” pilot project.)   In 2016, the legislature created the N.C. Policy Collaboratory at UNC-CH  and appropriated $500,000 a year for three years for the Collaboratory to study  and make recommendations concerning Jordan Lake water quality.  In the meantime,  the legislature appropriated $1.3 million in 2017 for another DEQ pilot project to test algaecides and phosphorus-locking technologies to control algal growth. Both  the Solar Bee and algaecide pilot projects failed. The nutrient management rules have continued to be suspended for completion of the UNC study. 

UNC Findings. The overall conclusions of the UNC report support the findings underlying the EMC’s 2009 nutrient management strategy:

♦ An effective nutrient reduction strategy requires measures to reduce both nitrogen and phosphorus releases to the lake.

♦ The sources of nutrient loading to Jordan Lake are nearly evenly divided between point sources (wastewater treatment plant discharges) and non-point sources (runoff from developed areas and agricultural operations). Non-point sources are a slightly greater contributor to nutrient loading.

♦ The Haw River contributes the greatest nutrient load to Jordan Lake, but other factors affecting movement and concentration of nutrients cause sources in the Upper New Hope arm of the lake to have a disproportionate impact on lake water quality. The 2009 EMC rules reflected a similar conclusion and required sources in the  Upper New Hope Arm of Jordan Lake to achieve greater nutrient reductions than sources in the Haw River watershed — a 35% nitrogen reduction versus an 8% reduction by Haw River communities.

♦  Runoff from developed land contains 10 times the concentration of nutrients than undeveloped lands; areas developed before 1980 generate significantly higher nutrient concentrations than those developed later.

♦ Wastewater treatment plant upgrades provide the most cost effective nutrient reduction  (in terms of pounds of nutrients removed per dollar invested). Riparian buffers and conservation of undeveloped lands are among the most cost-effective methods of reducing non-point source nutrient loading.

New lake and watershed models developed as part of the UNC study built on earlier models used by the EMC to develop the 2009 rules. The new modeling provides additional insight into the contribution of wastewater infrastructure to nutrient loading in response to storm events.

The UNC  report also concludes that measures to reduce new nutrient releases to Jordan Lake will show the greatest benefit over the long term because lake sediments have stored nutrients over time and release those nutrients back to the water column.

 UNC Study Recommendations.   First, the gaps. The recommendations don’t directly  address specific requirements of the  2009 Jordan Lake rules although most of the study’s findings support the scientific foundation and basic structure of the rules.  The UNC study reinforces the need to  reduce  both wastewater discharges of nitrogen and phosphorus and non-point source runoff  of nutrients to Jordan Lake. The study documents that non-point sources (runoff from developed areas and agriculture) account for more than 50% of the nutrient loading to Jordan Lake; developed areas contribute much more to nutrient loading than undeveloped areas;  and maintenance of vegetated buffers between developed areas and streams is one of the most cost-effective ways to reduce nutrient loading from non-point sources.

The lead recommendation in the UNC report is largely political; it focuses on how to  fund nutrient reduction strategies.  The legislature directed UNC to look at funding mechanisms in response to the objections of upstream communities in the Jordan Lake watershed  — particularly in the Haw River arm of the lake — to the cost of nutrient reduction measures  benefitting downstream communities. In response, the report identifies a water allocation fee  on local governments that receive drinking water from Jordan Lake as a possible funding mechanism.

Imposing a fee on downstream communities experiencing pollution of their drinking water supply by upstream pollutant sources would likely be controversial. It would also represent a significant policy change. Most state water quality programs impose  pollution reduction costs primarily on  the pollution source.  A number of existing state nutrient reduction programs in other river basins have followed that model. Communities in the Neuse River basin (including Raleigh) have implemented nutrient reduction programs similar to those required in the Jordan Lake rules for more than 20 years.  Those communities have absorbed the costs of pollution reductions to reduce nutrient-enrichment problems downstream in the coastal Neuse River estuaries.

Among the other UNC recommendations:

♦ Build local government support for nutrient management measures by emphasizing the local as well as downstream benefits.

♦ Review the existing state water quality standard for nutrient over-enrichment. DEQ has already asked a science advisory panel to review the current standard which is based on chlorophyl a concentrations. The UNC report recommends continuing the review and considering whether additional water quality parameters should be considered and applied depending on the uses of different sections of Jordan Lake.

♦ Consider relocation of sewer infrastructure to reduce the risk of leaks to streams and implement programs to address failing septic systems. (The 2009  Jordan Lake rules allowed local governments to include programs to address failing septic systems as one tool to meet nutrient reduction targets.)

♦ The recommendations highlight the value of land conservation as a tool for reducing nutrient loading. The recommendations do not mention the study conclusion that riparian buffers represent one of the most cost-effective ways to reduce non-point source nutrient loading.

♦ The report concludes that the relatively small amount of agricultural production  in the Jordan Lake watershed makes the Jordan Lake agricultural trading program ineffective.

The Takeaway.  Ten years and several million dollars later, the UNC report on Jordan Lake supports the decision by the EMC and the Department of Environmental Quality to develop a nutrient management strategy based on reduction targets for all of the major nutrient sources in the watershed — wastewater dischargers, development activity and agriculture. The report also confirms a number of the key scientific principles behind the rules — including  imposition of greater reduction targets on sources in the Upper New Hope arm of Jordan Lake and requiring reductions from both point and non-point sources.

The new lake and watershed models developed under the UNC study  build on those used to develop the 2009 Jordan Lake rules and provide additional  insights on the contributions of sewer infrastructure and septic systems. The study raises questions about the efficacy of the existing agricultural trading program.

Compared to the underlying studies, the executive summary has a decidedly political tilt — emphasizing the potential to reduce costs on upstream pollution sources by assessing a fee on downstream water users and downplaying legislatively unpopular — but cost effective — use of riparian buffers.

Editorial Comment.  The EMC and water quality program staff worked for  seven years to develop a fair and effective nutrient reduction program for Jordan Lake based on science and mediated by input from all of the affected parties. Rule development included several rounds of consultation with those potentially affected by the rules — local governments, developers, farmers, water users.   The UNC report supports the science behind the EMC nutrient strategy and  implicitly emphasizes the importance of implementing the strategy as soon as possible since the benefits  will only be realized over time.

The state has already lost nearly 10 years. The Jordan Lake nutrient strategy can — and should — be regularly reviewed and adapted based on new information. The UNC study suggests some areas for ongoing work. Nothing in the UNC study supports further delay.

One stakeholder is quoted in the report as saying: