10 Common Mistakes in STP Operations

By Mitch Panilag - Founder & President of Zoltech Water Solutions Inc.

10 Common Mistakes in ETP & STP Operations — And How to Avoid Them

Effluent Treatment Plants (ETPs) and Sewage Treatment Plants (STPs) are vital for environmental compliance, sustainability, and operational efficiency. Yet, many facilities underperform—not because of poor design, but due to avoidable mistakes in daily operation and maintenance.

At ZOLTECH Water Solutions Inc., we’ve audited and rehabilitated hundreds of treatment plants over the past 21 years. Our experience shows that small oversights in monitoring, training, or maintenance can lead to big problems in compliance and performance. Here are the 10 most common mistakes we see, and practical ways to prevent them.

1. Irregular Monitoring of Key Parameters

Mistake: pH, BOD, COD, TSS, and MLSS are not tested regularly.
Solution: Establish a fixed monitoring schedule. Automate testing where possible and maintain proper logs.

2. Poor Sludge Management

Mistake: Excess sludge is not removed on time, causing foul odors and reduced efficiency.
Solution: Monitor sludge levels in aeration tanks and clarifiers. Implement a desludging schedule.

3. Inadequate Operator Training

Mistake: Operators lack knowledge of biological processes and troubleshooting.
Solution: Conduct regular training workshops and refresher courses. ZOLTECH offers operator certification programs and PCO Masterclasses online.

4. Incorrect Chemical Usage or Dosage

Mistake: Overdosing coagulants or using substandard chemicals destabilizes the process.
Solution: Follow supplier recommendations and SOPs. Use calibrated dosing pumps.

5. Bypassing Pre‑Treatment Systems

Mistake: Screens, oil traps, and equalization tanks are ignored or bypassed.
Solution: Inspect and clean pre‑treatment systems regularly. They protect the biological process downstream.

6. Ignoring Preventive Equipment Maintenance

Mistake: Pumps, blowers, mixers, and diffusers are serviced only after failure.
Solution: Implement preventive maintenance checklists and keep critical spares in stock.

7. Poor Management of Shock Loads

Mistake: Sudden inflows of high organic or toxic loads disrupt treatment.
Solution: Use equalization tanks and train staff to recognize early signs of shock loads.

8. Lack of Flow Balancing

Mistake: Uneven influent flow leads to inconsistent performance and sludge washout.
Solution: Install flow meters and automation to balance inflows, especially during peak hours.

9. Weak Documentation and Recordkeeping

Mistake: Operational data is not properly recorded, making audits difficult.
Solution: Use logbooks, digital dashboards, and monthly performance reports.

10. Ignoring Seasonal Adjustments

Mistake: Plants operate the same way year‑round, ignoring temperature and load variations.
Solution: Adjust aeration, sludge recirculation, and dosing based on seasonal changes.

Final Thoughts

Running an ETP or STP is not just a compliance formality—it’s a commitment to responsible operations. Avoiding these mistakes improves performance, reduces costs, and protects your brand.

At ZOLTECH Water Solutions Inc., we deliver design‑build projects, system integration, consultancy, and turnkey solutions for small, medium, and large‑scale capacities. We also supply equipment, materials, chemicals, and provide advanced training programs to empower operators and Pollution Control Officers.

📞 Need Support?

If your plant is underperforming or you’d like a health audit, our team of experts is ready to help.

📧 Email: sales@zoltechwater.com
🌐 Website: www.zoltechwater.com