QuestionsQuestions (EXECUTIVE ORDER NO. 44)
To maintain the minimum water quality conditions necessary to assure the suitability of water for its designated beneficial use, by classifying waters and setting corresponding water quality criteria.
Water bodies are classified according to their beneficial uses, and each class has minimum criteria/limits that the water quality must meet so the water remains suitable for that use.
A water body can still be used for other purposes with lower classification (less stringent quality) as long as that broader/lower use does not prejudice the quality needed for the higher-class designated use.
Fresh surface waters: Class AA. Coastal/marine waters: Class SA.
By filing a petition with the DENR with necessary information. Reclassification must be adopted only after public notice and hearing and affirmative findings that: (i) it establishes present and future most beneficial use; (ii) it is clearly in the public interest; and (iii) the proposed designated use is attainable considering environmental, technological, social, economic, and institutional factors.
Dissolved oxygen (DO), pH, Biochemical Oxygen Demand (BOD), and Total Coliform organisms.
All surface waters shall be free from certain harmful non-thermal and thermal discharge components that create nuisances, floating/scum/debris, bad aesthetics, acute toxicity, carcinogenic/mutagenic/teratogenic risks, or serious danger to public health/safety/welfare, and thermal discharges that cause substantial harm or interfere with beneficial uses.
Non-thermal (domestic/industrial/agricultural/other man-induced) components and thermal components of discharges.
A minimum of 3.0 mg/L DO (as stated in the DO row for Class D).
Class AA: 1 mg/L (yearly average, with footnote context about parentheses being maxima). Class A: 5 mg/L.
Class AA: 50 MPN/100 mL; Class A: 20 MPN/100 mL (noting the footnote structure and that these values refer to geometric mean conditions over a 3-month period and exceedance rules).
They clarify that numerical limits are generally yearly average values, while values in parentheses are maximum values; other footnotes define how to apply limits (e.g., sampling periods, exceedance allowances, and special considerations like reservoirs).
Thermal components are prohibited if they create nuisance or increase the receiving body of water temperature to the extent that it causes substantial damage/harm to aquatic life or vegetation or interferes with the beneficial uses.
In Table 3 (conventional/oxygen demand/aesthetics) and Table 4 (toxic/deleterious substances) for coastal and marine waters. The difference is the classification set (SA, SB, SC, SD) and corresponding criteria.
A minimum of 50% saturation and 2.0 mg/L DO (as shown in the DO row for Class SD).
0.05 mg/L for both Class SA and Class SB.
Because samples for classification/compliance and effluent regulations must be analyzed using the methods enumerated in Table 5, ensuring consistent and legally acceptable testing procedures.
Sampling taken between 9:00 AM and 4:00 PM.