Water Quality and Wastewater Management

• Lecture 1 introduces water quality management

Environmental Functions

• Source: Water supply
• Consumption rate is less than or equal to regenerative capacity
• Sink: Wastewater management
• Pollution rate is less than or equal to assimilative capacity

Wastewater

• Combination of liquid or water-carried wastes is removed from households, commercial and industrial establishments, and institutions, along with groundwater and stormwater (if present).

Contents of Wastewater

• Organic materials include proteins, carbohydrates, fats, oils, and surfactants.
• Pathogens are disease-causing organisms such as e.coli, HEPA, rotavirus, and parasitic worms.
• Toxic compounds include heavy metals, pesticides, and solvents.
• Nutrients include nitrogen and phosphorus.

Emerging Pollutants

• Pharmaceuticals and personal care products (PPCPs)
• Microplastics and nanoplastics

Wastewater Engineering

• Applies science and engineering principles to address water pollution.
• Goal is to protect the environment while considering public health, economic, and social factors.

Wastewater Flowrates

• Determining flow rate is fundamental for designing wastewater collection, treatment, and disposal systems.

Ways to Estimate Wastewater Flow Rates

• Records or field measurements
• Water supply records

Components of Wastewater Flows

• Domestic (Sanitary)
• Commercial and Institutional
• Industrial
• Inflow/Infiltration

Wastewater Return Factor

• A portion of water that reaches the sewer system
• 65% to 85% of per capita consumption

Flow Rate Estimation for Design

Dry Weather Flow

• DWF = D + C + I + Ind + Inf
• C: Commercial
• I: Institutional
• Ind: Industrial
• Inf: Infiltration/Inflow
• D: Domestic

Average Dry Weather Flow

• Average flow rate over a 24-hour period.
• Used for evaluating wastewater treatment plant (WWTP) capacity.
• Used for estimating pumping and chemical costs, sludge solids production, and organic-loading rates.
• WWTP design considers flow rates, wastewater characteristics, and peaking conditions.

Peak Dry Weather Flow

• Maximum flow rate over a 24-hour period.
• Used for designing equalization basins and chlorine-contact tanks.
• PDWF = PF × ADWF
• PDWF: peak dry weather flow
• PF: peak factor
• ADWF: average dry weather flow

Wastewater Characteristics

• Understanding the nature of wastewater is essential for design and operation of wastewater facilities.
• Wastewater characteristics vary with treatment processes.
• Physical characteristics include color, temperature, turbidity, pH, and conductivity.
• Chemical characteristics include TSS, BOD, metals, and nutrients.
• Biological characteristics include bacteria, virus, and algae.

Regulations

DENR Administrative Orders

• DAO 1990-34 (Revised Water Usage and Classification): Water Body Classification
• DAO 1990-35 (Revised Effluent Regulations): Effluent Standards
• DAO 2016-08 (Water Quality Guidelines and General Effluent Standards)
• Primary: required minimum water quality parameters to be monitored for each water body
• Secondary: used in baseline assessment as part of Environmental Impact Assessment (EIA)
• DAO 2021-19 (Water Quality Guidelines and General Effluent Standards)
• EMB Statistics (Water Quality Management Data)

This lecture introduces water quality management, wastewater types and contents. It covers organic materials, pathogens, toxic compounds, nutrients and emerging pollutants. It also covers the goals of wastewater engineering.