PORT OF CORPUS CHRISTI DESALINATION: PROS & CONTROVERSY
The Port of Corpus Christi is seeking a Clean Water Act permit from the Texas Commission on Environmental Quality (TCEQ) for a planned desalination plant. In March 2018 the Port of Corpus Christi (POCC) submitted its permit application to TCEQ to discharge wastewater from the planned desalination plant. As of May 2023, POCC does not have a valid permit. The issue is that the United States Environmental Protection Agency (EPA) must approve the permit, and that agency says TCEQ did not
EPA is not the only party taking issue with the discharge permit. Audubon Texas, the Port Aransas Conservancy, and others contend that the wastewater from the desalination facility will harm the Bay of Corpus Christi.
Background
The planned desalination plant, to be located on Harbor Island near Port Aransas, would pump seawater from an adjacent channel and remove the salt, ultimately producing as much as 50,000,000 gallons of drinking water a day. Once the salt was removed, approximately 95.6 million gallons a day (MGD) of the wastes – primarily concentrated saltwater – would be discharged into the Corpus Christi Ship Channel, which leads to the Bay of Corpus Christi. Because the facility would discharge into these waters, it must comply with the Clean Water Act (CWA). Congress authorized EPA as the primary federal agency to administer the CWA.
This would be the first desalination facility in Texas to convert seawater into fresh water. Texas has 53 municipal desalination plants, and at least 300 industrial desalination facilities. In fact, the largest inland desalination plant in the world is in El Paso. It generates 27.5 MGD of fresh water from brackish groundwater, about half of what the POCC facility is designed to produce. The wastewater from the El Paso facility is piped for 22 miles before being injected underground. Wastes from Phase 1 of San Antonio’s desalination facility are piped about 12 miles.
The POCC desalination facility would use a process called reverse osmosis, which, roughly speaking, involves forcing the seawater through a membrane to filter out the salt The clean water would go to Corpus Christi, and the salinated discharge would go into the Ship Channel via an outfall pipe about 300 feet long. The outfall pipe has a diffuser with many holes to spread the discharge plume into the receiving waters. The fact that this discharged water would have a higher salinity than the seawater caused concern because high salinity can harm marine species, depending on the concentration of the salt, the duration of the exposure, and the species.
Clean Water Act Permits
The CWA prohibits discharging pollutants into waters of the United States which includes the Bay of Corpus Christi. Pollutants can include toxins, trash, chemicals, or even water at a different temperature or that contains sediments. This includes wastewater from a desalination facility. However, if a facility gets a permit known as a National Pollutant Discharge Elimination System 1 (NPDES) permit, it may discharge some pollutants as allowed under the permit. A NPDES permit sets limits on the types and/or quantities of pollutants to be discharged. The permit may also require the permittee to collect data or make modifications, such as using a filter, to reduce any harm to the environment from the discharged wastewater.
The CWA sets uniform standards for what discharges, known as effluents, may be released based on the type of industry. The list of industries, however, does not yet include desalination plants. Correspondingly, the list of effluent guidelines does not include the primary discharges from the POCC
1 NPDES is authorized under Section 402 of the CWA, codified at 33 U.S.C. § 1342.
desalination plant: chloride, sulfate, and total dissolved solids. (Essentially, these are salts.) When there are not specific effluent limits, EPA requires the “best professional judgment.”
Although the CWA is a federal law, it allows states to issue permits for wastewater discharges provided the permits are consistent with the law. The State of Texas and EPA entered into a Memorandum of Agreement establishing the terms under which TCEQ may issue permits for Texas facilities, known as TPDES permits (for Texas Pollutant Discharge Elimination System). However, even though TCEQ can issue the permit, EPA has the right to object if the permit does not meet the standards set under the CWA, effectively stopping the permit from being issued. 33 U.S.C. § 1342(d)(2).
The Cost of Desalination in Texas
Average cost to produce 1 acre-foot of desalinated water from brackish groundwater = $357 to $782.
Average cost to produce 1 acre-foot of desalinated water from seawater = $800 to $1,400.
One acre-foot = 325,851 gallons.
Source: Texas Water Development Board, Desalination Facts.
That’s what happened here. After public input and two triallike hearings (more on that later), Texas said it was issuing a TPDES permit December 20, 2022. However, EPA objected to the draft permit in 2021, asking TCEQ to provide additional information about the discharges and the environmental impacts from those salts. It appears TCEQ did not provide that information. Less than a month after TCEQ’s December 2022 announcement, EPA wrote TCEQ denying the permit’s validity: “it does not provide CWA authorization for the discharge of pollutants to waters of the United States from the Port of Corpus Christi Authority of Nueces County facility.”
Administrative Hearings
The discharge permit was controversial despite the need for freshwater in the area. Following a public comment period in which multiple parties including a State Legislator requested a hearing, TCEQ forwarded the matter to the State Office of Administrative Hearings, which is authorized to review TCEQ permitting disputes. An administrative hearing provides a direct route for opponents to a permit to have their objections reviewed in a trial-like setting. However, victory is not easy. The presumption under Texas law is that TCEQ has the familiarity, expertise, and judgment to issue a lawful permit. Thus, a TCEQ draft permit is “a prima facie demonstration” that the permit meets all state and federal legal and technical requirements. Basically, that means the draft permit is accepted as legally and technically correct and “would protect human health and safety, the environment, and physical property” if issued. Tex. Gov’t Code § 2003.047(i-1)(2). Accordingly, to stop TCEQ from issuing a draft permit, a party must demonstrate that the draft permit violates a “specifically applicable state or federal requirement.” Tex. Gov’t Code § 2003.047(i-2)(2).
Much of the controversy appears due to a lack of established standards for salinated discharge into Texas coastal waters and how those discharges affect endemic species. As mentioned, as neither TCEQ nor EPA establish effluent limits for chloride, sulfate, and total dissolved solids, those limits are up to the “best professional judgment” of the agency, which can be subjective. Additionally, TCEQ has not established surface water quality standards for salinity, and no salinity levels are reported for any of the state’s coastal water segments. The experts also dispute the impacts of the salinated discharge on marine species in the Bay of Corpus Christi, although there is agreement that the impacts are more significant on eggs and larvae than on older fish. Finally, while EPA and TCEQ have whole effluent toxicity testing protocols for marine species – testing the impact of all of the discharges, rather than just some components – those protocols do not require testing on red drum, and the parties all agree red drum larvae is the most impacted by high salinity. 2
First Administrative Hearing
Nine issues were advanced by TCEQ for Administrative Law Judges (ALJs) to review. Primarily, those issues involved whether the salinated discharges would have adverse impacts on the water quality and aquatic life of the Bay, although there also were procedural-type matters such as whether the application was complete and whether adequate public notice was given. Testimony and evidence were presented by all sides across six days in November 2021. 3 At the conclusion, the ALDs issued a Proposal for Decision 4 (PFD) that TCEQ deny the permit.
Some specific issues related to the discharged wastewater were:
• Whether the proposed discharge would adversely impact the marine environment, aquatic life, birds, endangered or threatened species, spawning, or larval migration [of fish larvae];
• Whether the proposed discharge would adversely impact fish and other seafood making it unsafe for human consumption; and
• Whether the Executive Director of TCEQ’s modeling of the discharges used accurate input data to ensure the wastewater was protective of water quality.
The ALJs found the discharges did not pose a threat to human health. However, they took issue with the remaining two matters: the discharge’s impacts on the environment of the Bay of Corpus Christi, and the computer modeling by TCEQ.
2 See EPA, Chronic Toxicity to Marine and Estuarine Organisms (referring to sheepshead minnow, inland silverside, mysid, and sea urchin).
3 Disclosure: Dr. Greg Stunz, Senior Executive Director of the Harte Research Institute for Gulf of Mexico Studies, testified on behalf of the Port Aransas Conservancy, an opponent to the permit.
4 Citations to the PFDs will be to the page numbers printed on the document, or to a Finding of Fact (FF).
Antidegradation Review
The Texas Water Code (TWC) and its regulations require TCEQ to conduct a review to ensure that a discharge will not change the water quality of certain receiving waters by more than a “de minimis” amount. The term “de minimis” is not defined by Texas law or regulation, but the applicable TCEQ standards treat increases of less than 10 percent as de minimis. However, specific numeric criteria for salinity are not established for any Texas bay. This leaves it up to experts to determine whether a discharge will increase the salinity of the Bay of Corpus Christi by 10 percent or more.
How Salty Is Saltwater?
Saltwater can be classified based on the amount of total dissolved solids (TDS) it contains in milligrams per liter.
Freshwater: TDS <3,000 mg/l
While TCEQ’s expert found the wastewater discharge would not pose more than a de minimis impact, opponents’ experts disagreed. They testified that the salinity in the Corpus Christi Ship Channel was already “close to the physiological tolerance of the most sensitive species” in the area – red drum – and that any increase threatened marine life. PFD p. 37. According to some testimony, the salinity of the Corpus Christi Ship Channel ranged between 18 parts per thousand (ppt) and 39 ppt. Other testimony suggested the salinity at the zone of initial dilution (ZID) where the outfall pipe was located would be as high as 78.5 ppt. The opponents’ experts claimed that fish larvae migrating through the ZID would be exposed to acutely toxic levels of salinity, perhaps killing as many as 20,000,000 fish a year. Although TCEQ and POCC disputed those conclusions, noting the ZID was a small portion of the channel and that the channel’s overall salinity would increase by no more than 1 percent, the ALJs found that “the proposed discharge will likely result in the loss of life and other adverse effects on early life stages of fin and shellfish, including their larvae, in the ZID.” PFD FF No. 89.
Brackish water: TDS >1,000 mg/l and <10,000 mg/l
Saline water: TDS >10,000 mg/l
Modeling the Discharge
Brine: TDS >10,000 mg/l
Seawater: TDS >35,000 mg/l
Sources: Texas Water Development Board, Desalination: General FAQs; EPA
Many of the disputes regarding the impact of the discharges were related to the computer modeling performed by TCEQ to imitate how the wastewater plume would move in the channel. Opponents to the permit claimed TCEQ used inaccurate data. For example, the wastewater plume was modeled on the outfall location being where the channel is 63 feet deep, but in fact, the channel at that location is 90 feet deep. The water velocity input was 0.05 meters per second (m/s), but 68 percent of the time the velocity in that area exceeds 0.41 m/s. The ALJs found the modeling was inaccurate.
Conclusion to the First Administrative Hearing
Overall, the ALJs found “the draft permit does not include all appropriate and necessary requirements.” PFD p. 83. On February 5, 2021, the ALJs issued its PFD to deny the permit.
Second Administrative Hearing
TCEQ considered the ALJs’ Proposal for Decision and directed POCC to give all parties revised information about the depth and velocity of the channel where the outfall diffuser would be located. Also, TCEQ found the ALJs imposed stricter limits on the ZID’s toxicity than the regulations required, among other things, and it remanded (a legal term for returned) the matter to the ALJs.
An administrative hearing on remand was held in March 2022. The ALJs were the same, the parties were the same, and six of the nine original issues were still in dispute. Accordingly, the testimony and evidence was similar.
Antidegradation Review
Once again, the parties disputed whether the discharge’s impact on the Bay’s water quality was de minimis. The opponents’ expert witnesses testified that the salinated discharges “will likely lead to a significant decrease in biodiversity within the bay” causing both lethal and sub-lethal effects such as body size, impaired reproduction, or the inability to avoid being eaten. PDF on Remand p. 74. The ALJs concluded that the salinated discharge “would not necessarily raise the salinity level of the receiving water to an alarming level” (emphasis added). PDF on Remand p. 51.
The judges suggested that water quality would be unimpaired by the discharges: “[TCEQ’s] antidegradation review demonstrates that the proposed discharge will maintain existing uses and not lower water quality by more than a de minimis amount.” PDF on Remand FF 78. But they concluded that a “salinity permit limit” was needed, adopting the recommendation of the Texas Department of Parks & Wildlife and the General Lands Office for a 2.0 salinity limit over ambient levels as measured 100 meters from the outfall. PDF on Remand
Other Texas Desalination
The Kay Bailey Hutchinson desalination facility in El Paso has a maximum production capacity of 27.5 MGD, and it is the world’s largest inland desalination plant, converting brackish groundwater into drinking water.
Source: Texas Water Development Board
The first phase of the San Antonio desalination plant has a maximum production capacity of 12 MGD. It also converts brackish water into drinking water.
Source: LBG-Guyton Associates (March 3, 2017)
pp. 53, 33. It may seem incongruous to find that the draft permit complied with the law but also to require a change to that permit to make it compliant.
Modeling the Discharge
Once again the parties disputed the accuracy of the computer modeling of how the discharge would mix with the ambient water. In the first hearing the ALJs had found that inaccurate inputs were a material factor in recommending denial of the permit. PFD p. 32. In the second hearing, opponents to the permit claimed several of the input values for the revised outfall point were still wrong, albeit wrong in different ways. This time POCC said the outfall would be located in 90-ft deep waters, but the actual depth was 65 feet. Opponents argued POCC also used the wrong input for the length to shore, and faulted TCEQ for not using the same brine model as in the first hearing to assess how a sloping bank at the outfall location would affect the discharge plume. Finally, opponents contended that the swings in the measured ambient velocity of the Ship Channel (-1.25 m/s to +1.4 m/s) indicated the outfall location was at an eddy, which could change how the salinated discharge mixed with the ambient water.
The modeling discrepancies seemed to yield more favorable results for POCC’s preferred outfall location. By modeling the outfall diffuser at a location deeper than where it would be built, the analyses perhaps identified lower salinity levels based on a larger volume of water than would occur or may not correctly identify how the heavier wastewater stratifies in the water column. In fact, the ALJs found that another imprecise input, the slope of the channel floor, “will overpredict mixing.” PFD on Remand FF No. 58. Additionally, the judges found an eddy may occur but it was not a permanent eddy. Overall, the ALJs agreed with opponents that some imprecise inputs were used in the revised application but found that those inputs did not affect the accuracy of the modeling. The judges found the “modeling inputs are either within the range of reasonable values or are not materially inaccurate.” PFD on Remand p. 40. However, the ALJs stated the uncertainty “supports the need for setting a permit limit on the salinity of the discharge.” PFD on Remand p. 40.
Ultimately, the ALJs concluded that a permit should be issued if it required the salinity limit described above. TCEQ issued the permit on December 20, 2022, imposing a 2.0 ppt salinity limit at 100 meters, as well as setting three additional salinity limits closer to the outfall location. However, on January 19, 2023, EPA wrote TCEQ indicating that the permit of December 2022 was not in compliance with the CWA and “it does not provide CWA authorization for the discharge of pollutants to waters of the United States from the Port of Corpus Christi Authority of Nueces County facility.” This left POCC without a valid permit.
EPA Involvement
EPA told TCEQ that it was not satisfied with the POCC permit application or the draft permit as early as September 2021. In its September 2021 letter, EPA took issue with TCEQ’s characterization of the draft permit being for a “minor facility,” which would mean, among other things, that EPA had no final say in
the permit’s issuance. EPA asked for documents, and upon reviewing those documents, it issued an Interim Objection in December 2021 indicating it found some problems with the draft permit that needed to be addressed in order to comply with the CWA. According to EPA’s January 2023 letter denying the validity of the permit, TCEQ never resolved the Interim Objection.
Under the CWA, EPA has the final say in issuing permits, even if most issuing authority was delegated to the state. That delegation occurred via a Memorandum of Agreement (MOA) between Texas and EPA. In the MOA, EPA waived its permit oversight in some circumstances, such as for minor facilities. EPA took issue, however, with categorizing the POCC facility as a minor facility.
Under the MOA, minor facilities either discharge less than 0.5 MGD or those discharges contain nonprocess wastewater. However, water containing a waste product is considered process wastewater under the definitions for both Texas and EPA. Notably, POCC indicated in its application that it was discharging process wastewater – 95.6 million gallons a day when fully operational, meaning it was not a minor facility. EPA confirmed this, further describing the desalination operation as discharging “wastewater generated by a reverse osmosis process that contains high concentrations of salt and other impurities relative to the seawater feedstock.” EPA provided notice to TCEQ on September 2021 that it was revoking its waiver for this and all future Texas desalination facilities’ discharge permits.
As a result, no valid permit is in place for the POCC desalination plant. And it seems unlikely that either TCEQ or POCC could force EPA to approve the December 2022 permit. The procedures to challenge discharge permits at different stages are established by the CWA. Under 33 U.S.C. § 1342(d)(4), a party has 90 days after an Interim Objection to request a hearing by EPA. Neither POCC nor TCEQ appear to have made a timely request for a hearing. According to EPA in its January 2023 letter to TCEQ, TCEQ issued the permit “without responding to the Environmental Protection Agency’s Interim Objection.”
The CWA offers another avenue for review, this time by a court via 33 U.S.C. § 1369(b)(1)(F), which authorizes federal appellate courts to review whether permits were properly issued or denied. However, under established caselaw, it is unlikely that a court would order a hearing. Multiple federal Courts of Appeals have considered challenges to discharge permits that EPA objected to. In all of the cases, the courts denied the challenges, finding that although 33 U.S.C. § 1369 provides for judicial review of discharge permits, it authorizes reviews only after EPA has issued or a denied a permit. 5 EPA does not consider an objection to be either an issuance or a denial of a permit, and neither did the courts. While these courts’ decisions are not binding on the Fifth Circuit Court of Appeals, which has jurisdiction over such cases that occur in Texas, it is likely that the Fifth Circuit would find the precedent persuasive.
5 Southern California Alliance of Publicly Owned Treatment Works v. U.S. Environmental Protection Agency, 853 F.3d 1076 (9th Cir. 2017); American Paper Institute, Inc. v. U.S. Environmental Protection Agency, 890 F.2d 869 (7th Cir. 1989); Champion International Corp. v. U.S. Environmental Protection Agency, 850 F.2d 182, 190 (4th Cir. 1988).
Conclusion
Opponents to the permit disputed multiple factors regarding a desalination plant in Corpus Christi; yet the main problem was unspoken: they oppose its location. Certainly the technology exists to extend pipelines miles into the Gulf of Mexico. This would add to an already expensive enterprise, but possibly one with fewer impacts from the salinated discharge. However, opponents’ effort to overturn the permit allowing discharge into the Corpus Christi Ship Channel failed. Instead it was EPA that halted the project for the time being.
The future of the discharge permit is unclear. EPA, not TCEQ, now has the authority to issue the discharge permit for the POCC desalination plant. That is true whether EPA chooses to issue a permit based on POCC’s revised 2018 application or for any future desalination discharge permit.