Question & AnswerQ&A (DENR ADMINISTRATIVE ORDER NO. 97-23)
The purpose of DENR Administrative Order No. 97-23 is to maintain the quality of Philippine waters in a safe and satisfactory condition according to their best usage, updating the water classification and water quality criteria, specifically amending sections of DAO No. 34, Series of 1990.
Class SA waters are those suitable for the propagation, survival, and harvesting of shellfish for commercial purposes, national marine parks and marine reserves, and coral reef parks and reserves established or declared by law and concerned authorities.
Class SB waters include tourist zones and marine reserves primarily used for recreational activities such as bathing, swimming, and skin diving; Recreational Water Class I areas regularly used by the public for similar activities; and Fishery Water Class I spawning areas for Bangus and similar species.
Class SC waters are for Recreational Water Class II activities such as boating, Fishery Water Class II used for commercial and sustenance fishing, and marshy and/or mangrove areas declared as fish and wildlife sanctuaries.
Class SD waters are for industrial and Water Supply Class II uses, such as cooling, and include other coastal and marine waters that do not meet the quality criteria of the other classifications.
The maximum allowable fecal coliform count in Class SB waters is 200 Most Probable Number (MPN) per 100 milliliters, based on the geometric mean of at least five consecutive sampling events.
Sampling should be done at regular intervals at least six times a month when there are indications of pollution, with possible reduction during low bathing activity periods or when pollution sources are effectively controlled.
Samples should be collected at locations with at least 1 meter depth and from water 20-30 centimeters below the surface.
Procedures regarding sample containers, sample collection, sample preservation and handling, chain-of-custody, sample analysis, and quality assurance/quality control must be strictly observed.
The order took effect fifteen (15) days after publication in two newspapers of general circulation.