Surface water quality monitoring is vital for safeguarding ecosystems, drinking water sources, and industrial processes. The 5-parameter approach—tracking **pH, dissolved oxygen (DO), conductivity, turbidity, and temperature**—provides a foundational assessment of water health. This guide explains the significance of each parameter, compliant testing tools, and actionable strategies aligned with ISO and EPA standards.
These indicators collectively reveal:
- Pollution risks (e.g., chemical spills, nutrient runoff).
- Ecosystem stress(e.g., hypoxia, algal blooms).
- Compliance status with regulations like the EU Water Framework Directive.
1. pH Level
- Ideal Range: 6.5–8.5 (WHO for aquatic life).
- Why It Matters:
- Low pH (<6.5): Acidic water leaches metals (aluminum, lead), harming fish.
- High pH (>8.5): Indicates algal blooms or industrial alkali discharges.
- Testing Standard: ISO 10523 (electrometric method).
2. Dissolved Oxygen (DO)
- Healthy Range: >5 mg/L for fish survival; <2 mg/L causes dead zones.
- Why It Matters:
- Low DO signals organic pollution (e.g., sewage, agricultural runoff).
- Critical for wastewater treatment efficiency.
- Testing Standard: ISO 5814 (Winkler titration) or ISO 17289 (optical sensors).
3. Conductivity
- Purpose: Measures ion concentration (salinity, TDS).
- Baseline Values:
- Freshwater: 50–500 µS/cm.
- Polluted/Industrial: >1,000 µS/cm.
- Testing Standard: ISO 7888 (electrode method).
4. Turbidity
- Purpose: Indicates suspended solids (sediment, algae, pollutants).
- Safe Threshold:
- Drinking water sources: <1 NTU (EPA).
- Aquatic ecosystems: <50 NTU (ISO 7027).
- Testing Tools: Nephelometers (ISO 7027-compliant).
5. Temperature
- Impact:
- Affects DO solubility (cold water holds more oxygen).
- Triggers thermal pollution from industrial discharges.
- Monitoring: Follows ISO 5667-3 sampling guidelines.
Multi-Parameter Sondes
Recommended：ERUN-SP7Multi-parameter water quality analyser（You can email for a quote on the information）
- Features:
- Submersible, real-time data logging.
- Anti-fouling wipers for long-term deployment.
- Compliance: Meets ISO 17289 (DO), ISO 7027 (turbidity).
- Challenge: Industrial pollution reduced DO to <2 mg/L in stretches.
- Solution:
- Deployed 100+ IoT buoys to monitor 5 parameters in real time.
- Enforced stricter discharge limits based on EPA conductivity thresholds.
- Result: DO levels improved to >5 mg/L, reviving aquatic biodiversity.
Monitoring pH, DO, conductivity, turbidity, and temperature forms the backbone of surface water management. By adopting ISO 5667 and EPA standards—and leveraging advanced tools like multi-parameter sondes and IoT buoys—governments and industries can prevent ecological collapse, ensure compliance, and protect public health.
