STANDARDS FOR DOMESTIC WASTEWATER: REGULATIONS AND KEY INDICATORS

STANDARDS FOR DOMESTIC WASTEWATER: REGULATIONS AND KEY INDICATORS

I. Why Do We Need Standards for Domestic Wastewater?

Domestic wastewater includes wastewater from daily human activities such as bathing, washing, cooking, and sanitation. It contains various pollutants, including organic substances, nutrients (nitrogen and phosphorus), bacteria, viruses, detergents, and other chemicals. Without proper treatment, domestic wastewater can pollute the environment and severely affect public health. Therefore, setting standards for domestic wastewater is crucial to control and mitigate its negative impacts.

II. Domestic Wastewater Standards in Vietnam

In Vietnam, domestic wastewater standards are defined in QCVN 14:2008/BTNMT - National Technical Regulation on Domestic Wastewater, issued by the Ministry of Natural Resources and Environment. The regulation specifies important indicators as follows:

1. Basic Indicators of Domestic Wastewater:

• pH (Acidity/Alkalinity): The standard pH range is 5.5 - 9.0. This ensures that the wastewater is neither too acidic nor too alkaline, which could harm the environment and ecosystems.
• BOD₅ (Biochemical Oxygen Demand in 5 Days): This is a key indicator showing the amount of oxygen needed to decompose organic matter in the water. The BOD₅ limit for domestic wastewater ranges from 30 - 50 mg/L, depending on the treatment type and discharge area.
• COD (Chemical Oxygen Demand): The COD indicator reflects the amount of organic substances in wastewater, with limits from 50 - 100 mg/L.
• TSS (Total Suspended Solids): TSS indicates the amount of insoluble solids in wastewater, with limits from 50 - 100 mg/L.

2. Nutrient and Microbial Indicators:

• Ammonium (NH₄⁺): Ammonium is a key indicator to assess nitrogen pollution in wastewater, with a limit of 5 - 10 mg/L.
• Nitrate (NO₃⁻) and Nitrite (NO₂⁻): Nitrate and nitrite are nitrogen-containing compounds that can contaminate groundwater. The limit is 30 mg/L for nitrate and 0.05 mg/L for nitrite.
• Total Phosphorus (P): The phosphorus limit is 4 - 6 mg/L to prevent eutrophication.
• Coliform Bacteria: This is a crucial indicator to assess microbial contamination, with a limit of 3000 MPN/100mL.

3. Toxic Chemical Indicators:

• Heavy Metals (Pb, Hg, As, Cd): Heavy metals in domestic wastewater need strict control due to their significant health risks. The limit is typically < 0.05 mg/L for these metals.
• Detergents (Surfactants): The limit for synthetic detergents is 5 mg/L.

III. Classification of Domestic Wastewater Standards

Domestic wastewater standards in Vietnam are divided into two main categories:

• Category A: Applicable for wastewater discharged into water bodies used for domestic water supply.
• Category B: Applicable for wastewater discharged into water bodies not used for domestic water supply.

Category A has stricter limits to ensure the safety of water sources used for community drinking water.

IV. Factors Affecting Domestic Wastewater Quality

The quality of domestic wastewater can vary due to several factors:

• Type of Activity: Residential areas, restaurants, hotels, and hospitals generate different quantities and types of wastewater pollutants.
• Population Density: The number of users affects the flow and quality of wastewater.
• Treatment Systems: The technology and processes used in domestic wastewater treatment play a significant role in ensuring compliance with standards.

V. How to Improve and Ensure Domestic Wastewater Standards

1. Adopt Advanced Treatment Technologies:

   • Use modern technologies like AO, AAO, SBR, MBR, and MBBR to enhance treatment efficiency and reduce pollutants.

2. Strict Monitoring and Management:

   • Increase inspection and monitoring of discharge facilities to ensure compliance with domestic wastewater standards.

3. Raise Community Awareness:

   • Educate the public on water conservation, reducing the use of detergents and harmful chemicals in daily activities.

VI. Domestic Wastewater Treatment Services at VIET WATER JOINT STOCK COMPANY

Viet Water Joint Stock Company offers high-quality domestic wastewater treatment services, helping clients comply with legal regulations and protect the environment.

• Address: 345 Pham Van Bach, Ward 15, Tan Binh District, Ho Chi Minh City
• Manufacturing Facility: Thanh Xuan 52 Street, Thanh Xuan Ward, District 12, Ho Chi Minh City
• Tax Code: 0312931928
• Phone: 028.6272.4888 - 0904.506.065
• Email: info@vietwaterjsc.com – manager@vietwaterjsc.com

We provide comprehensive solutions from consulting, design, to construction of domestic wastewater treatment systems using advanced technologies, ensuring quality and full compliance with regulatory standards.

Contact us today for the best support and advice on domestic wastewater treatment services!