The Local Health Authority at the municipal or city level shall identify the list of parameters that will be examined to determine the potability of drinking water supply provided in the local area.
Based on its health significance and acceptability, the following priority parameters shall be tested:
14. Total Dissolved Solids ( TDS )
In addition to the above, other physical and chemical parameters shall be tested based on the following conditions:
1.1 All naturally occurring chemicals based on the geological characteristics in the local area that are of health significance and are found in drinking-water supply should be in the priority list.
1.2 An inventory of chemicals used in local agricultural practices such as pesticide, herbicide and fungicides shall be the basis for identifying which the organic constituents (pesticides) to include in the priority list.
1.3 Industries that transport, use as raw materials, produce either as intermediate or final product or by-product or generate as wastes any or all of the chemicals listed in PNSDW 2006 shall be identified and mapped. Water sources taken within 50 meters from the location of the said industries should be examined for such chemicals.
1.4 Chemical disinfection by-products shall be identified based on the type of disinfectants used. If water providers could provide evidence of control of generation of disinfection by-product such as pretreatment to remove precursors, use of treatment technology that evidently removes disinfection by-product or two successive analysis showing that suspected by-product does not occur then such chemical disinfection by-products will be removed from the priority list.
1.5 Chemicals leaching from plumbing system materials or facilities such as copper, lead, zinc and nickel shall be included in the list if the pH of water is 6 or below.
1.6 Hardness will only be in the list if the general population deems it unacceptable at certain level due to taste or odor.
1.7 The list of priority physical and chemical parameters to be monitored may change based on the results of previous water examinations. Parameters that are less likely to occur in water may be tested less frequent.
2.1 Radiological quality shall be included in the priority list if there is fall-out or contamination from suspected sources of radiological impurities of water such as hospitals or other industries.
2.2 Sources of naturally occurring radiological contaminants should be identified by the Department of Health or Philippine Nuclear Research Institute