Abstract
A study was conducted to investigate the current status of saltwater intrusion in the northern coastal aquifer of Ilocos Norte. Specifically, the study aims to determine the following: the degree of possible salt water intrusion; to identify the possible causes of risks associated with salt water intrusion and to come up with mitigation measures suitable in the locality. The study area was characterized based on its geophysical and hydrological factors. The cropping patter practiced is predominantly rice-garlic-vegetables. Groundwater resources are being used both for domestic and agricultural purposes. Groundwater samples were collected from the farmers 21 existing shallow tubewells (STW) in three coastal barangays of Pasuquin, Ilocos Norte. Collection of samples were done using a portable sampling pump wherein the STWs were purged for 10 minutes prior to collection to pump out possible impurities. Groundwater samples collected were placed in 1 liter nalgene bottles, properly labelled and kept in an ice chest. The samples were immediately submitted to the Regional Testing Center of DOST-I, San Fernando, La Union for chloride and calcium analyses. Results of analyses showed alarming results especially on chlorides content of groundwater samples. Average chloride content of seven STWs per barangay reached 650.0 mg/liter which is above the recommended limit of 250.0 mg/liter (Ayers, 1976) for irrigation water and 5.0 mg/liter for domestic purposes. Therefore, the chloride content of groundwater samples analyzed posed an alarming threat to the coastal aquifer under study. There is a possible encroachment of saltwater intrusion to the STW’s in farmers’ field. A recommendation to undertake a mitigation technique to reduce saltwater intrusion using freshwater technology both in a hypothetical and actual coastal aquifer system is deemed necessary. This would serve as source of management strategies to solve if not to halt the saltwater intrusion landwards, thus protecting the coastal aquifer systems.
Source or Periodical Title
Transactions of the National Academy of Science and Technology
Page
59
Document Type
Article
Frequency
Annualy
Language
English
Subject
Risk assessment; Chlorides; Groundwater
Recommended Citation
Taclan,, Lorcelie B., "Risk assessment of saltwater intrusion" (2021). Journal Article. 6.
https://www.ukdr.uplb.edu.ph/journal-articles/6