Corpus Christi sits at the center of one of the most concentrated petrochemical corridors on the Gulf Coast. Refineries, chemical plants, and industrial facilities line the harbor and Corpus Christi Bay, and the city’s water infrastructure has operated in close proximity to this industrial activity for generations. In December 2016, that proximity produced a crisis that put the city’s water supply on the national news and raised serious questions about how well the water system was protected from industrial contamination.
The 2016 Chemical Backflow Incident
On December 14, 2016, the City of Corpus Christi issued a do-not-use order for the entire municipal water system — one of the most sweeping water advisories in Texas history, affecting over 300,000 residents. The cause was a backflow event at an industrial facility that allowed an industrial chemical, Indulin AA-86 (an asphalt emulsification agent), to flow backward into the city’s water distribution system through an improperly maintained or absent backflow preventer.
The chemical entered at a connection between the city’s water system and a local industrial user. City officials and state regulators scrambled to assess the extent of contamination. The Texas Commission on Environmental Quality (TCEQ) was notified and began oversight of flushing and testing operations.
Indulin AA-86 is not acutely toxic in small concentrations, but its presence in drinking water represented a serious regulatory violation and a failure of the backflow prevention infrastructure designed to keep industrial contaminants out of public supplies. Residents were told not to drink, cook with, or bathe in tap water. Schools closed. Stores ran out of bottled water within hours.
The city flushed the distribution system and tested water at hundreds of points before lifting the order days later. The incident led to investigations, audits, and eventually legislative changes at the state level requiring more rigorous backflow prevention inspections statewide.
Industrial Water Quality Context
The 2016 incident was dramatic, but it happened against a backdrop of longer-term water quality concerns in the Corpus Christi area. The city’s industrial ship channel and surrounding industrial facilities have been associated with a range of environmental issues over the years.
The Corpus Christi Ship Channel and the surrounding bays have documented histories of contamination from petroleum products, heavy metals, and other industrial discharges. The EPA’s Toxics Release Inventory shows industrial facilities in the Corpus Christi metro area release significant quantities of chemicals that can affect local water bodies.
Corpus Christi draws its drinking water primarily from the Choke Canyon Reservoir and Lake Corpus Christi, which are connected by a system managed by the Nueces River Authority. These surface water sources are subject to agricultural runoff, including nitrates and pesticides from upstream farming areas, as well as sediment inputs. Treatment at the city’s O.N. Stevens Water Treatment Plant includes conventional coagulation, filtration, and disinfection.
What the Data Shows
The City of Corpus Christi publishes an annual Consumer Confidence Report (CCR) that lists contaminants detected in the finished water. In past reports, contaminants detected above zero but below EPA action levels have included:
- Trihalomethanes (TTHMs): A disinfection byproduct formed when chlorine reacts with organic matter. Surface water sources with higher organic content tend to produce more TTHMs during treatment.
- Haloacetic acids (HAAs): Another class of disinfection byproduct with similar formation pathways.
- Nitrates: From agricultural runoff in the Nueces River watershed.
- Arsenic: Present at low levels in some Texas groundwater sources. [NEEDS VERIFICATION: current arsenic levels in Corpus Christi supply]
The city’s system has generally maintained compliance with EPA Safe Drinking Water Act standards, but compliance does not mean zero detections — it means detections below legally enforceable limits.
The Environmental Working Group’s Tap Water Database has flagged Corpus Christi water for levels of some contaminants that, while legally compliant, exceed EWG’s more conservative health guidelines. Disinfection byproducts are the primary concern.
Harbor and Bay Contamination
Corpus Christi Bay and the ship channel have their own contamination profiles that matter for fish consumption and recreational water use, even if they’re separate from the drinking water supply. The Texas Department of State Health Services has issued fish consumption advisories for certain species from the bay and ship channel, citing concerns about dioxins and PCBs in sediment. [NEEDS VERIFICATION: current active advisories]
La Quinta Channel, which runs through the heart of the industrial corridor, has been cited in EPA enforcement records for industrial stormwater discharges. Industrial facilities along the channel have faced penalties and consent orders over the years for various Clean Water Act violations.
What Residents Can Do
- Read the CCR. The City of Corpus Christi publishes its Consumer Confidence Report annually. Look at the detected contaminant levels and compare them to both EPA MCLs and EPA health advisory levels.
- Ask about backflow prevention. The 2016 incident revealed gaps in the system’s industrial connection safeguards. Ask your city council representative about the status of mandatory backflow preventer inspection programs.
- Test for TTHMs and HAAs. These disinfection byproducts are regulated but worth measuring in your own tap water, especially if you have a whole-house or under-sink filter you’re not sure is working effectively.
- Private well users should test independently. If you rely on a private well in the Corpus Christi area, test for petroleum hydrocarbons, heavy metals, and nitrates given the proximity to industrial and agricultural sources.
- Follow fish advisories. If you fish in the bay or ship channel, check DSHS advisories before eating your catch.
Water Treatment Options
For disinfection byproducts like TTHMs and HAAs, activated carbon filtration is effective. Under-sink carbon block filters or whole-house GAC systems can significantly reduce these contaminants. Reverse osmosis systems handle a broader range of contaminants including nitrates and many industrial chemicals.
For residents who want broad-spectrum protection given the industrial context of Corpus Christi, a certified NSF/ANSI 58-rated reverse osmosis system offers the most comprehensive reduction of regulated and unregulated contaminants.
The 2016 chemical intrusion incident was a wake-up call, and the systems put in place afterward have strengthened protections. But Corpus Christi’s position at the center of heavy industry means water quality vigilance is a permanent part of life here.
If you are concerned about your water quality, a certified water treatment professional can test your water and advise on solutions.