Law Summary
General Water Quality Requirements for Surface Waters
- Surface waters must be free from non-thermal and thermal pollutants that cause nuisance, toxicity, carcinogenic/mutagenic/teratogenic effects, or pose public health dangers.
- Thermal discharges must not raise water temperature to levels that harm aquatic life, vegetation, or beneficial uses.
Water Quality Criteria for Fresh Waters
- Parameters affecting aesthetics and oxygen demand are set with specific limits per classification (Classes AA to D), including color, temperature rise, pH, dissolved oxygen, BOD, suspended solids, dissolved solids, surfactants, oil/grease, nitrates, phosphates, phenolic substances, and coliform counts.
- Toxic and deleterious substances such as arsenic, cadmium, chromium, cyanide, lead, mercury, and specific pesticides have maximum allowable concentrations depending on water class for protection of public health.
- Specific notes apply to parameters such as seasonal averaging, sampling times, and application of certain standards only to lakes or reservoirs.
Water Quality Criteria for Coastal and Marine Waters
- Similar parameters and limits apply to classes SA to SD for aesthetics and oxygen demand, including color, temperature rise, pH range, dissolved oxygen, biochemical oxygen demand, suspended solids, surfactants, oil/grease, phenolic substances, and coliform counts.
- Toxic substances have class-specific limits aligned with those for fresh waters where applicable.
Approved Methods of Water Analysis
- Water samples for classification and compliance must be analyzed using prescribed methods such as colorimetric, atomic absorption spectrophotometry, gas chromatography, membrane electrode, and gravimetric methods.
- Methods correspond to specific water quality parameters like arsenic, BOD, cadmium, chromium, cyanide, dissolved oxygen, coliforms, lead, mercury, oil/grease, phenolics, surfactants, temperature, and suspended solids.
- Other standardized analytical methods may be used as determined by the DENR.
Parameters of Significant Concern for Specific Industries
- The regulation identifies key wastewater parameters to monitor for various industries, including beverage, cement, dairy, ferro alloy, fertilizer, grain milling, inorganic chemicals, leather tanning, livestock, canned goods, meat, metal finishing, mining, organic chemicals, petroleum refining, plastics, pulp and paper, steel, sugar processing, textile, and thermal power generation.
- Parameters include biochemical oxygen demand, pH, suspended solids, oil and grease, heavy metals (e.g., chromium, cadmium), phenols, colors, and toxic materials.
Implementation and Effectivity
- The order takes effect 30 days after publication in the Official Gazette or a newspaper of general circulation.
Important Notes and Definitions
- Beneficial use classification may consider intended future uses influenced by political, economic, social, and environmental factors.
- Numerical limits often represent yearly averages with maximum limits indicated in parentheses.
- Certain parameters do not apply if natural background concentrations exceed the standards, in which case natural background prevails.
- Symbols such as (nil) denote concentrations below detection limits, (---) indicate standards not currently necessary, and (nr) means no recommendation made.
- Laboratory procedures and compliance sampling times are standardized for consistency and reliability.
- The classifications and criteria reflect a balance between environmental protection and socio-economic development needs.