The most common type of salmon aquaculture is in net pens located in marine environments. Species Directory: Atlantic Salmon (Farmed), NOAA Fisheries (June 22, 2023). Inland farming of salmon is rarer and traditionally in ponds. In recent years, inland salmon farming in enclosed facilities has gained traction because of its potential to pose fewer environmental risks than coastal aquaculture. Although emerging technologies for aquaculture in enclosed environments such as recirculating aquaculture systems (RAS) currently account for less than 1% of the production of salmon species globally, data suggest that this is changing. Tim Sprinkle, Competitiveness Comes at Scale for RAS Operations, Glob. Seafood All. (Mar. 8, 2017). RAS technology proponents are poised to significantly influence the aquaculture industry in the coming decade. Projections indicate that by the year 2030, 40% of the U.S. production of salmon will be through RAS. Recirculating Aquaculture Salmon Network (RAS-N), Building Capacity of Land-Based Atlantic Salmon (Salmo salar) Aquaculture in the United States (2022).
Influenced by industry predictions, the U.S. government has set its sights on the development of the domestic land-based RAS industry. In 2019, the Maryland Sea Grant program and the University of Maryland in Baltimore County received a $1.2 million grant from NOAA’s National Sea Grant Office to study and enhance the production of Atlantic Salmon through RAS. Maryland Sea Grant, UMBC Awarded $1.2 Million National Aquaculture Grant, Md. Sea Grant (Sept. 19, 2019). Furthermore, in October 2022, the National Sea Grant Office granted $425,000 to the Great Lakes Aquaculture Collaborative to study the potential for land-based RAS in the Great Lakes region. NOAA Greenlights 425k for Land-Based Aqua Project in Great Lakes Region, Fish Site (Oct. 24, 2022). As federal money is pouring into research to advance the technology of RAS aquaculture, the need for regulating this emerging industry has gained impetus nationwide.
Several U.S. states, such as California, Maine, and Maryland, lead the surge in the development of industrial RAS facilities. This article focuses on the issue of siting RAS facilities in Maryland, as illustrated by a case study reflecting the AquaCon RAS facility proposals. Even though the state is at the forefront of the research of RAS technologies, its regulatory framework has yet to be updated to support this emerging industry. Like any type of development, conflicting interests are almost unavoidable; however, proper regulatory tools at both local and state levels can ameliorate tensions, prevent prolonged and contentious siting processes, and minimize potential harm to communities and the natural environment.
Land-Based RAS Technology
RAS is a cutting-edge method of cultivating fish and aquatic organisms by recycling the water used in their production. RAS technology employs mechanical and biological filters that can be adapted for the aquaculture of various species, including fish, shrimp, and clams, but it is predominantly employed in finfish farming. Jacob Bregnballe, A Guide to Recirculation Aquaculture (2022). Salmon RAS facilities raise the fish in tanks with highly controlled environments and reuse the water to minimize reliance on water resources. Within a facility, there are multiple sizes of tanks that accommodate salmon in different life stages; usually, each tank includes a double drain system to facilitate the removal of solids. Removing these solids—primarily fecal matter and uneaten food—requires mechanical filtration. Filtered water is then treated through biofiltration, which removes dissolved waste from the water before it is recirculated back into the tanks.
RAS facilities require continuous water supply to maintain the required water level in the tanks. The volume of consumptive water use associated with RAS facilities depends on the amount of water that can be recycled or reused. Currently, many RAS facilities worldwide operate within enclosed and insulated buildings, utilizing as little as 300 liters of freshwater per kilogram of fish produced. Id. at 1. When denitrification and phosphorus removal are integrated into the RAS circuit, water consumption can be further reduced to only 30–40 liters per kilogram of fish produced. Id.
The water discharged from RAS facilities is usually both lower in volume and higher in quality compared to more conventional systems of aquaculture, such as flow-through systems. The reduced water usage simplifies and lowers the cost of removing nutrients excreted by the fish because the volume of discharged water is significantly lower. In addition, the nutrients from the farmed fish can be repurposed as fertilizer for farmland or used in biogas production, and the solid waste filtered from the water may be converted to fuel-grade biogas to offset the energy cost of the RAS facility.
The conservation of water in RAS can seem very attractive when compared to conventional aquaculture systems, particularly in areas where water scarcity has been exacerbated by climate change. However, it is still important to note that water usage in RAS facilities can vary substantially depending on the number of fish produced. Smaller facilities tend to recycle more water and have less or even zero discharge. Large or industrial facilities have thus far been less successful in optimizing their water use and recycling methods, which means that these facilities still have a significant intake and discharge of water. As described in the case study, water consumption and discharge continue to pose challenges for siting and permitting these facilities.
The RAS design directly influences how and where a facility obtains and discharges water. For instance, one approach only requires the intake of freshwater. In this design, the facility intakes freshwater and uses a special formula to produce salt water to simulate the living environment for salmon. The resulting wastewater discharge from these facilities is a combination of sanitary wastewater, seafood processing wastewater, and purge water. The purge water is freshwater that is used to remove the off-flavor caused by compounds such as Geosmin (GSM) (C12H22O) and 2-methylisoborneol (MIB) (C11H20O), produced by bacteria, including cyanobacteria and actinomycetes, already present in saltwater and freshwater. P.C. Lindholm-Lehto et al., Depuration of Geosmin-and 2-Methylisoborneol-Induced Off-flavors in Recirculating Aquaculture Systems (RAS) Farmed in European Whitefish Coregonus lavarettus, 56 J. Food Sci. & Tech. 10 (2019). GSM and MIB accumulate naturally in fish gills and skin and concentrate in fish tissue from the circulating water.
Siting a RAS Facility in Maryland: The AquaCon Case Study
Maryland’s aquaculture industry has existed for centuries, with its most prominent sector being oyster aquaculture along the Chesapeake Bay. In recent years, land-based salmon RAS aquaculture has gained traction in the state due to the funding received by the University of Maryland for the research of this technology. In 2019, AquaCon Maryland LLC ventured out to develop an industrial RAS facility in the state and selected two potential sites: the City of Cambridge in Dorchester County and the Town of Federalsburg in Caroline County. The siting process in Cambridge failed due to heightened concerns that the facility would interfere with existing land uses. AquaCon failed to permit the Federalsburg site due to concerns over potential harm to an Atlantic sturgeon, an endangered species, resulting from the proposed purge water discharge. These two obstacles to the AquaCon RAS facility—land use (in Cambridge) and water discharge (in Federalsburg)—are examined below.
The siting of the AquaCon facility in the City of Cambridge was complicated because the zoning ordinances and land use regulations did not contemplate RAS-type facilities. For example, the local zoning ordinances’ definition of “aquaculture” did not address land-based RAS. Art. IX, Uniform Development Code, City of Cambridge, Md., § 9.2. Efforts to fit the RAS proposal into the framework contemplated by state and local law were challenging.
In Maryland, most local governments have the power to regulate their own zoning and land use. This is commonly referred to as home rule. Zoning categories can vary by local government, but some common zoning types include residential, industrial, and commercial (or business) zones. Land use activities such as agriculture and aquaculture are regulated by the local governments under these zoning categories. However, there is some flexibility for activities that are not usually permitted in certain zones. Under those circumstances, project proponents may request variances or special exceptions. Furthermore, in addition to basic local zoning requirements, in the case of Maryland, there are overlay zones that developers must take into consideration to ensure compliance with certain state regulations such as the Chesapeake Bay Critical Area Program.
The site selected in the City of Cambridge, Dorchester County, was a former country club. The proposed facility was approximately 1.2 million square feet, and the Cambridge Water & Sewer Treatment Plant was expected to receive 70–80,000 gallons of domestic wastewater per day from the RAS facility. Dorchester County, Md. Board of Appeals Meeting Minutes (Nov. 5, 2020). The proposed location was within the Rural Residential—Resource Conservation Area District, which means it is in a residential zone with a Maryland Critical Area Program overlay. Art. VII, District Regulations, Dorchester Cnty., Md., Code § 155-32. To build an RAS facility in this zoning district, AquaCon needed to go through two processes: first to get approval from the State Critical Area Commission under the Department of Natural Resources, and second to obtain a special exception from the Dorchester County Board of Appeals.
In this case, the Critical Area Commission approved the project with the condition that its approval would “be subject to a detailed site plan review.” Dorchester Cnty. Minutes, supra. AquaCon then requested the approval of the special exception to the Dorchester County Board of Appeals, but the approval was denied. Based on the zoning ordinances that listed criteria for special exception considerations, the Board found that the RAS facility would not be in harmony with the general character of the neighborhood, which is mainly residential housing. Dorchester Cnty., Md., Code § 155-20.C. The Board also noted that the RAS facility would have a detrimental effect on the economic value of surrounding properties and vehicular and pedestrian traffic due to the large volume of trucks that would transit in and out of the area. Lastly, the Board of Appeals raised concerns about the operation’s potential to overburden existing public services.
Under Dorchester County’s current zoning and land use definitions and requirements, it seemed possible for AquaCon to be sited within a Rural Residential-Resource Conservation Area. Dorchester County’s ordinance clearly states that land-use activities for aquaculture are allowed, subject to the approval of a special exception by the Board of Appeals. Aquaculture is defined in the zoning ordinance as “[t]he farming or culturing of aquatic plants and/or animals in natural or man-made water bodies or buildings but excluding shedding operations as herein defined.” Id. § 155-13. Furthermore, under the local Critical Area Program, “[l]and-based aquaculture” is defined as “[t]he raising of fish or shellfish in any natural or man-made, enclosed or impounded, water body.” Id. § 68-1. However, neither definition truly captures the type of land use activities required by RAS facilities. Given the scale of the proposed AquaCon facility (approximately 27.54 acres), it would be quite different from the traditional type of aquaculture done on land, such as pond aquaculture, and thus the original categorization of land use and zoning for inland aquaculture activities would not be appropriate. Dorchester Cnty. Minutes, supra.
These land use issues were not a concern when AquaCon turned to the second site: the Town of Federalsburg in Caroline County. This site was located in the Frank Adams Industrial Park. Initially, the town made a rather welcoming gesture to this new industry, amending in 2020 the zoning ordinance to include a definition of land-based aquaculture tailored to AquaCon’s RAS operation. The revised zoning codes explicitly defined land-based aquaculture as “farming or culturing of finfish, … in tanks or impoundments, including hatching, cultivating, planting, feeding, raising, and harvesting of aquatic plants and animals and the maintenance and construction of necessary equipment, buildings, and growing areas.” Town of Federalsburg, Md., Code § 245-6. The town also added “aquaculture, land-based” as its 76th permitted use in the Industrial District ID-2, which was planned to accommodate a diverse range of activities, including light manufacturing, fabricating, processing, wholesale distribution, and warehousing. Id., art. XIII, General Industrial District ID-2, Code § 245-80.
Even though AquaCon overcame the issue related to zoning and land use in the Town of Federalsburg, the company faced a new challenge: obtaining a water discharge permit from the Maryland Department of the Environment (MDE). Under the National Pollutant Discharge Elimination System (NPDES) program, industrial RAS facilities that meet certain production thresholds are considered concentrated aquatic animal production facilities (CAAPs), which are point sources under the Clean Water Act. The NPDES permitting program places restrictions on quantities, rates, and concentrations of the pollutants that are discharged from point sources into navigable waters. Clean Water Act, 33 U.S.C.A. § 1362(11). States such as Maryland with approved NPDES programs are authorized to issue permits within their jurisdictions. Id. § 1342(b)(1)(A).
In this case, AquaCon applied for an NPDES permit to discharge “2.3 million gallons purge water per day” into Marshyhope Creek. AquaCon Presentation to MDE, Surface Water Discharge Permit, MDE Informational Meeting (May 26, 2021). The primary issue related to the potential impacts associated with the discharge of “purge water” from the facility to Marshyhope Creek and whether the discharge would have impacted a federal-and-state-listed endangered species, the Atlantic sturgeon (Acipenser oxyrinchus). Marshyhope Creek is the spawning and nursery habitat of the Atlantic sturgeon and designated as a critical habitat for the species. Habitat Designation for Atlantic Sturgeon, NOAA Fisheries (2021). MDE acknowledged scientists’ concerns related to the point of discharge, characterized as a shallow channel over 100 feet wide. Those concerns highlighted the potential for the purge water to inundate the entire channel and affect both the sturgeon spawning cues and the growth and survival of their offspring. Dave Secor, AquaCon Salmon Factory Jeopardizes Maryland’s Only Sturgeon Population, Balt. Sun (Aug. 18, 2022).
Other concerns related to purge water discharges included temperature and constituent concentrations. MDE’s permit would have allowed discharges of wastewater with lower temperatures than Marshyhope Creek’s ambient temperatures, which could impact the spawning of sturgeon. Timothy B. Wheeler & Jeremy Cox, Maryland Regulators Tentatively Approve Wastewater Permit for Massive Salmon Farm, Bay J. (Aug. 2, 2022). Furthermore, the concentrations of salinity and phosphorus in the proposed discharge also raised concerns because the Marshyhope Creek was already identified as an impaired waterbody due to existing high concentrations of phosphorus and nitrogen. Id. On May 4, 2021, the Maryland Department of Natural Resource’s Chief of the Environmental Review Program also sent MDE a letter raising concerns about the potential impact of the construction of the land-based aquaculture facility to the Atlantic sturgeon and its critical habitat. Letter from the Md. Dep’t of Nat. Res. to Md. Dep’t of Env’t (May 4, 2021).
To quell these concerns, AquaCon issued statements indicating that the impact of the purge water would not be significant. Mainly, the company argued that the primary area of the potential sturgeon spawning habitat is concentrated in the lower six miles of Marshyhope Creek, approximately 10 miles downgradient from the project site. AquaCon Presentation to MDE, supra. Despite these statements, on October 14, 2022, AquaCon ultimately withdrew from developing the RAS facility in the Town of Federalsburg because of the substantial public opposition. Press Release, AquaCon, AquaCon Withdraws Marshyhope Creek Discharge Permit Application (Oct. 14, 2022).
Takeaways from the AquaCon Case Study
The case of the AquaCon RAS facility in Maryland provides three main lessons for state and local practitioners nationwide: (1) the importance of updating zoning ordinances to accommodate land-based RAS facilities, (2) the potential benefits of siting RAS facilities in industrial zones such as brownfield sites, and (3) the need for states to provide regulatory and technical support to local governments.
As demonstrated in the case study, one of the central challenges for siting RAS facilities is the ambiguity and lack of modern classifications within local zoning ordinances that could accommodate RAS-type facilities. Ensuring that zoning regulations specifically and unambiguously accommodate RAS aquaculture practices is key to the growth of this industry in Maryland and nationwide. RAS is a highly industrialized and technologically advanced form of aquaculture that does not fit neatly into existing zoning categories. To foster a conducive environment for RAS and address community concerns, jurisdictions should adopt a forward-looking approach, introducing clear and specific zoning amendments to define the activities associated with RAS and ensuring that those activities are allowed in industrial districts.
Another way that local governments can encourage the development of RAS facilities is by siting such facilities in existing industrial zones such as brownfield sites. Brownfield sites—previously developed lands that may be polluted—represent a unique opportunity. These sites, in most cases, are already zoned for industrial use and may align with the needs of RAS facilities because the sites will likely contain pipelines for water usage, discharge, and wastewater treatment. The redevelopment of these sites further provides an avenue for sustainable land use, turning neglected or contaminated areas into productive, job-creating ventures. This approach has been adopted in several places in the United States, like the Nordic Aquafarms RAS facility in Humboldt County, California, and the Whole Oceans and Xcelerate Aqua facilities in Maine. Ultimately, repurposing brownfield sites for RAS would combine economic growth with environmental rehabilitation.
In addition to local zoning considerations and brownfield redevelopment, states’ regulatory and technical efforts can play a significant role in shaping the future of RAS siting. In the case of AquaCon, the state’s direct involvement with the project happened when the company applied for water usage and discharge permits after potential site selection. It is important for the state entities that will be involved in the process of regulating RAS facilities to take proactive measures to build the capacity of local governments to be better prepared to regulate the siting of land-based RAS facilities with an approach that is tailored to this emerging industry. Furthermore, the establishment of clear and consistent regulatory requirements for land-based RAS facilities by states could help the industry and local governments prepare for the siting of these facilities, ameliorate potential environmental harms, and appease public opposition.
RAS offers a promising avenue for sustainably boosting U.S. domestic salmon production. The benefits from RAS are clear: It has the potential to decrease water consumption and reduce environmental impacts from salmon farming in addition to creating jobs and bolstering local economies. However, the realization of these advantages hinges on a regulatory framework tailored to the industry’s specific siting requirements. Effective governance will be crucial for RAS technology to fulfill its potential as the most sustainable form of aquaculture.
