Corpus Christi: As Inner Harbor Desalination Plant Proceeds, Harbor Island Desalination Plant in Doubt
Feature Photo: Looking northward at the southeast end of Harbor Island, located between Aransas Pass and Port Aransas. The outlined area is where the Port of Corpus Christi Authority proposes to construct a seawater desalination plant. Image: Google Earth/VBX graphic.
by Adolfo Pesquera
Corpus Christi (Nueces County) — After many years of planning, delays and some setbacks, this much can still be said–the City of Corpus Christi and the Port of Corpus Christi Authority remain at the forefront of efforts to establish seawater desalination plants in Texas.
Texas does not have an operational seawater desalination facility. In fact, there are very few large operational facilities for municipal use in the United States.
Tampa Bay Seawater Desalination Plant, Tampa, Florida, with a design capacity of 25 million gallons per day (MGD)
Claude “Bud” Lewis Carlsbad Desalination Plant, Carlsbad, California, with a design capacity of 50 MGD.
According to the Dec. 1, 2020 biennial report to the Texas Legislature from the Texas Water Development Board, there are six recommended seawater desalination projects throughout the Gulf Coast. However, the most advanced project is one being developed by the City of Corpus Christi.
Note: While there are plans for six seawater desalination plants, the TWDB is assisting many municipalities across the state with the design and construction of brackish water desalination plants. The difference between the two is that brackish water is salty or otherwise contaminated well water that is drawn up from the ground, not the open sea.
The City of Corpus Christi’s Inner Harbor Ship Channel SDP is the only project that has progressed from the planning stage to the permitting stage.
Other entities in the Corpus Christi Bay area involved in seawater desalination include the Port of Corpus Christi Authority, Corpus Christi Polymers (formerly known as M&G Resins USA LLC), Seven Seas Water, and Poseiden Water in partnership with the City of Ingleside (Pankratz, 2020).
The City of Corpus Christi and the Port of Corpus Christi Authority are government entities that are independent of each other. However, over the years they both have had an interest in forming partnerships with industries and other stakeholders.
In 2015, the City of Corpus Christi funded and participated in a feasibility study on seawater desalination for industrial purposes alongside 14 other stakeholders consisting of industries, water providers and regional authorities.
Since industrial stakeholders use 50% of the region’s municipal water supplies, they considered developing seawater desalination as potential new water supplies to ensure service continuity to industrial customers in the event of extreme drought.
The study concluded that stakeholders preferred to build two plants, each with a capacity of 10 MGD. This led to the proposed siting of a plant on the Inner Harbor Ship Channel, with a second plant to be located on the La Quinta Ship Channel.
The July 2020 loan from the TWDB to the City of Corpus Christi had two purposes–the pursuit of permits for two sites, and the design-build of a seawater desalination plant with a capacity of 30 MGD at one of the two sites.
The one plant to be constructed is to have an initial capacity of 20 MGD, with the ability to expand to its full capacity in the future.
On Sept. 20, 2020, the city invited some entities to present on their alternative water supply projects, submitted in response to the request for information.
In October 2020, the TWDB, with technical assistance from HDR Engineering Inc. issued its 2021 Regional Water Plan for the Coastal Bend (Region N), which includes 10 counties. The counties of Nueces, San Patricio and Aransas are among the 10.
As explained in the October 2020 report, the Port of Corpus Christi Authority (PCCA) has taken the lead in developing two seawater desalination plants–one on the La Quinta Channel and one at Harbor Island, which is located in the intracoastal waterway between Aransas Pass and Port Aransas.
Harbor Island SDP:
The Harbor Island project is proposed to produce 50 MGD for both municipal and industrial use, utilizing reverse osmosis to treat seawater, and a diffuser would discharge into the Corpus Christi Ship Channel.
Construction of the facility would impact approximately 33 acres in a former fuel tank storage area, which is currently vacant.
The water rights permit has not yet been submitted for the Harbor Island project because a review of available data is underway to determine intake placement in the Gulf of Mexico. The Texas Commission on Environmental Quality discharge permit was filed in 2018.
The discharge permit was ruled administratively complete, and the public comment /meeting process completed. There was a public meeting in Port Aransas in April 2019. In response to the TCEQ Executive Director’s recommendation that the TCEQ Commissioners grant the discharge permit, the City of Port Aransas, PAC, and others petitioned for a contested case hearing.
TCEQ Commissioners directed the permit to the State Office of Administrative Hearings (SOAH) for a contested case hearing.
On Feb. 5, 2021, the Port Aransas Conservancy won its protest to the proposed discharge permit. Two administrative law judges of the SOAH recommended to TCEQ that they deny PCCA’s discharge permit application.
“After considering the evidence and argument the Port Authority has not met its burden to prove that the proposed discharge will not adversely impact the marine environment, aquatic life, and wildlife, including spawning eggs and larval migration,” the SOAH administrative law judges stated in their recommendation.
The PCCA’s president and CEO Sean Strawbridge told the Caller Times the decision could have a “drastic and detrimental impact” on the region’s ability to provide enough water. He expressed the hope that the TCEQ would disregard the recommendation and instead support the position of its own executive director.
Modeling completed by the PCCA, indicates that brine discharge released from the desalination plant would increase the ambient concentration less than 1% beyond the aquatic life mixing zone. They conclude that this increase would be insignificant compared to the natural variation in salinity observed in Corpus Christi Bay.
The total estimated cost for a 50 MGD facility located in Harbor Island is $802,807,000.
The project assumes construction of a 22-mile pipe to San Patricio County and a 2-mile 42-inch pipe to Nueces County.
There would be three pipe segments: 21 miles of 42-inch diameter, 1.2 miles of 36-inch diameter, and 2.3 miles of 24-inch diameter.
The La Quinta site is located near the La Quinta Ship Channel in San Patricio County. It will produce 30 MGD for primarily industrial use, utilize reverse osmosis to treat seawater from Corpus Christi Bay, and a proposed diffuser would discharge into the La Quinta Ship Channel.
Approximately 27 miles of pipeline will be used to deliver water to customers in the area. The TCEQ permit for the La Quinta Channel project was filed on September 3, 2019; TCEQ is reviewing additional information to make completeness determination; and public comment occurred in December 2019.
Total estimated costs for a 30 MGD facility at La Quinta are $457,732,00.
The project also assumes construction of a 3-mile, 48-inch pipeline for delivery to the industrial complex in San Patricio County.
Details regarding intake, desalination process, concentrate disposal outfall, site-specific environmental impacts, and storage needs were not available at the time of the October 2020 report, and therefore not included in the cost estimate.
Adolfo Pesquera (Reporter/Editor) is a veteran news journalist. He has worked for Hearst Corp., American Lawyer Media, News Corp and Freedom Communications. His work has been published in newspapers and magazines across the USA. He is a journalism graduate of UT-RGV. He writes, edits and creates digital pages for VBX.