The facility location at Harbor Island allows for sustainable and unlimited growth of the water supply commensurate with demand growth over time without impact to the surrounding ecosystem.
Why is this location suitable for long-term needs of the region?
Natural conditions in the project area, including bathymetry and the proximity to the Gulf of Mexico allow for sufficient mixing and water exchange to prevent an increase in ambient salinity over time.
[Water Supply 2-pgr]
Ambient salinity levels near the proposed discharge location vary naturally and marine species passing through Aransas Pass are naturally adapted to these varying salinities.
[Water Supply 2-pgr]
The facility location at Harbor Island allows for sustainable and unlimited growth of the water supply commensurate with demand growth over time without impact to the surrounding ecosystem.
[Water Supply 2-pgr]
Location of actual desal facility on HI
Proposed diffuser / discharge location
What is a high velocity diffuser? A high velocity diffuser is a physical structure designed to rapidly disburse – in this case – a concentrated salinity effluent. [Doug 2022 PPT]
Where will it be installed? Corpus Christi Ship Channel (“CCSC”), a disturbed body of water (Not in the Aransas Inlet, Not in the RBSSC, Yes, within EFH (as are all United States waters)) [Doug 2022 PPT]
The diffuser will be installed 65 feet below the surface of the water, is 30 meters long, and has 20 nozzles pointed upward (~ 30 degree angle to horizontal). The location, position, and discharge perpendicular to the flow of the channel promote rapid disbursement and dilution of salinity
Proposed intake location
Placement of the intake structure offshore in the Gulf of Mexico is protective of estuaries, bays, and marine life
The proposed location allows for future expansion without future impacts. [Water Supply 2-pgr]
Environmental effects of the project
Studies and testing show that the proposed discharge will not result in significant degradation of water quality or impacts to aquatic life in the CCSC or the bay system.
[Water Supply 2-pgr]
Modeling shows that, during operation of the facility under the full range of ambient conditions, greater than 92% of the Corpus Christi Shipping Channel cross section is unaffected by the facility’s discharge.
[Water Supply 2-pgr]
Sensitive species exposure to elevated salinity is very limited
[Doug 2022 PPT]
Exposures above 45 ppt for seconds (not hours or days)
Higher saline plume is not on or near the water surface and will avoid most sensitive larvae
Protective of red drum [Doug 2022 PPT]
Limited exposure to elevated saline conditions is not harmful to red drum eggs or larvae
Published literature demonstrates red drum tolerance to higher salinity
Toxicity testing demonstrates tolerance
References
[Doug 2022 PPT]
Robertson (1988): ‘results show no effect at 45 ppt (red drum larvae)’
Brauner (2013): ‘red drum (adults) at 80-110 ppt; lack of recruitment at 60 ppt’
Stunz (HRI) (2015): ‘CC Bay resident species tolerate 28-42 ppt’
Kesaulya (HRI) (2018): ‘Red drum eggs/larvae hatch and growth best at 33-43ppt’
Esbaugh (UTMSI) (2021): ‘Red drum “quickly acclimate to hypersalinity” (30 to 60 ppt)’
Nielsen (UTMSI) (2021): ’24h NOEC to red drum eggs/larvae at 45 ppt’
Studies indicate that the proposed intake will not result in significant degradation of water quality or impacts to aquatic life
Permits required
TPDES for discharge from desalination facility (TCEQ)
The Port of Corpus Christi submitted its NPDES permit application in May 2018. The TCEQ subsequently issued a draft permit to the Port of Corpus Christi, which was then referred to the State Office of Administrative Hearings (SOAH) for a contested case hearing. The SOAH issued a ruling in May 2021and the TCEQ remanded the permit application for revisions. The Port Authority submitted a revised application in [date] and it, along with additional analysis by TCEQ, was presented to SOAH for consideration. On [date] SOAH issued a PFD recommending issuance of the discharge permit.
TCEQ’s administrative record is available here.
Water Rights (TCEQ)
TPDES General Permit for Hydrostatic Test Water (TCEQ)
TPDES Construction General Permit (TCEQ)
TPDES General Permit for Petroleum Contaminated Water (TCEQ)
Solid Waste Generator Registration (TCEQ)
CWA 404/Section 10 for diffuser installation (Army Corps)
CWA 404/Section 10 for intake installation (Army Corps)
CWA 404/Section 10 for intake pipeline (Army Corps)
State Lease or intake structure (GLO)
State Easement for intake pipeline (GLO)
On-site sewage (Local Health Department)
Floodplain Development Permit (Local Floodplain Management District)
City Building Permits (Local Municipalities)