THE Davao City Disaster Risk Reduction and Management Office (CDRRMO) warned residents living along Suawan River and Davao River tributaries to avoid swimming and fishing in the river following a chemical spill.
On August 1, 2022, a truck transporting sodium hydroxide or caustic soda crashed and fell 50 feet off a cliff into a ravine in Brgy. Suawan, Calinan.
“Delikado man gud ni siya, it's very harmful, makapaso ni siya sa atong panit, magsuka ang tao, maka-diarrhea and difficulty of breathing (This is a harmful chemical because it can cause skin burn, vomiting, diarrhea, and difficulty of breathing),” Alfred Baloran, CDRRMO Head said in an interview on the Davao City Disaster Radio on August 2, 2022.
Caustic soda or lye is widely used as a cleaning agent in industrial and manufacturing set ups. Being high in akali, the chemical is highly corrosive to animal and vegetable tissue.
It is also used for soap making, candle making, homemade biodiesel, frosting glass, making several food, and for chemistry experiments.
Project coordinator Lemuel Manalo of the Interfacing Development Interventions for Sustainability (Idis) added that caustic soda in high concentration may lead to skin burns for humans especially when it’s handled without proper protective equipment.
“It’s not a friendly chemical na madaling i-tolerate ng humans (that we can easily tolerate). If you touch the water, possible na may skin burns especially doon sa concentrated areas (you could have possible skin burns especially if you are in a concentrated area),” Manalo said in an interview.
He added that the chemical spill will have direct damage to the environment of the incident site and its surrounding area where the chemical spill is concentrated.
Particularly, Manalo said the sodium characteristic of caustic soda will impede the quality or pH level of the affected body of water resulting in higher temperatures and higher pH level leading to an unbalanced freshwater environment of Davao River, which in turn can result to loss of aquatic life.
Baloran said even though the tank truck only spilled a minimal amount of chemicals in the area, they discovered that some fish had died in the Suawan River. The incident is expected to affect the whole Davao River system.
“Dili lang sa ta mangaligo ug mangisda kay gina-examine sa atoang mga concern offices ang kaning tubig sa sapa kung unsa gyud ang effect sa sodium hydroxide (caustic soda) sa Davao River (Avoid swimming and fishing in the affected area since we are still examining the water to determine its effect),” Baloran said.
Meanwhile, the City Health Office (CHO) said that the Sanitary Inspection (SI) Unit already conducted water testing to check the water contamination in the Suawan River.
Manalo suggested water treatment be done to address the spill but it would be challenging.
“Kapag mabilis ang river flow, ang discharge rate niya, mas mabilis rin ang pag contaminate ng pollutants sa iba’t-ibang areas ng Davao River. May pwedeng gawin as treatment pero hindi na siya as effective because we cannot predict anymore yung coverage ng spillage because of the water flow (If the river flow is fast, the discharge rate is also faster and pollutants can spread quicker in areas of the Davao River),” Manalo said.
He added, “Ang best thing that we could hope is by a natural process, for example, the rain that would help dissolve the sodium hydroxide.”
Manalo said the best option would be to monitor the Davao River and its water quality through its pH level, salinity, and water temperature. He said if the state of the water is still high in alkaline and sodium, it could affect the entire ecosystem, and the ban on fishing and other water activities may be prolonged.
Meanwhile, Manalo said Idis is working on a review of the contingency plan for managing toxic spills to be proposed to the city government. The contingency plan will be a guideline for environmental agencies and other concerned organizations.
“Sana maging learning lesson ito sa atin (Hopefully this would be a learning lesson to us) in dealing with similar accidents in the future, at least we are prepared to take immediate action,” he said. ICM with KSD