Calculation of the Potential to Cause Pipe Corrosion of Available Freshwater in the Shallow Aquifer Water Resource in San Narciso, Zambales, Region 2 of the Philippines 

Jayvee Villagracia¹, Gerna Manatad², Plormelinda Olet³, Ralph Lago⁴, Raymond Sucgang*⁵

1.Commission on Elections (COMELEC)

2.Department of Health (DOH)

3.National Intelligence Coordinating Agency (NICA)

4. Philippine Drug Enforcement Agency (PDEA)

5. Philippine Nuclear Research Institute (PNRI), Diliman, Quezon City

Email: cesarsed2002@gmail.com

The study aimed to determine the scaling potential of groundwater in San Narciso. Zambales using the Langelier Saturation Index (LSI).  Groundwater samples from deep wells, hand pumps and dug wells were collected within the study area (Barangays Grullo, La Paz, Dalipawen, Paite, Siminublan, and Manatakan). LSI of groundwater from La Paz ranged between -1.0 -0.3 suggesting that waters were seriously corrosive. LSI in Paite was 0.0 but pitting corrosion was possible. Grullo waters have LSI between 0.1 to 0.3 and is scale forming and corrosive. Dalipawen, Siminublan, and Manatakan have LSI from 0.4 -0.0 and waters were slightly corrosive but not scale forming. LSI is based on the carbonate equilibrium in water. LSI was calculated using the formula: LSI = pH- pH_s; where pH_s is the saturation pH. The elements that are important for the carbonate equilibrium are gaseous carbon dioxide CO₂, aqueous carbon dioxide (CO₂)_aq, carbonic acid H₂CO₃, bicarbonate HCO₃^-, carbonate CO₃^2- and solids containing carbonate like calcium carbonate CaCO₃ or magnesium carbonate MgCO₃. It was concluded that groundwater in San Narciso, Zambales was generally slightly corrosive and scale forming. The baseline data from the study will be useful to water resources managers.

Keywords: Langelier Saturation Index (LSI), groundwater, corrosion, pH, carbonate