Commercial Sewage Treatment System Service – Forfar

We recently completed a scheduled six-monthly service on a complete commercial wastewater treatment system in Forfar.

The system consists of a grease trap, Marsh aerated sewage treatment plant and twin three-phase final effluent pump chamber. Servicing the complete system during one scheduled visit allows each stage of the wastewater treatment process to be inspected, cleaned and tested.

Grease Trap Service

The grease trap serving the sewage treatment plant is fitted with an outlet grease and fat filter together with a high-oil alarm system.

The high-oil alarm probe was removed, cleaned and reinstalled before the alarm was tested and confirmed to be operating correctly.

The outlet grease and fat filter was also removed, thoroughly cleaned and correctly re-seated. Keeping this filter clean helps reduce the amount of solid fats and grease passing forward into the primary settlement tank of the sewage treatment plant.

At the time of the service, the grease trap contained approximately 250mm of crust and 200mm of sludge.

Marsh Sewage Treatment Plant Service

The Marsh aerated sewage treatment plant was operating correctly, with good and even fine-bubble aeration throughout the treatment zone.

No excessive foaming or abnormal odours were identified during the inspection.

The electrical control panel and internal wiring were in good condition. The timers, loss-of-pressure alarm and solenoid valve were all tested and confirmed to be operating correctly.

Becker Blower & Aeration System

The treatment plant is fitted with a Becker 3CR800D air blower.

The blower was operating correctly at 1.6A, with no abnormal noise or vibration identified. The air intake filter was replaced during the service and all associated air lines were inspected and found to be in good condition.

All diffusers were individually scoured and cleaned to reduce sludge accumulation and help maintain efficient air transfer throughout the treatment process.

Final Effluent Quality

The treatment process was operating correctly at the time of the service, with good final effluent clarity and good observed discharge quality.

An onsite turbidity reading of 20 was recorded.

The primary settlement tank contained approximately 250mm of crust and 100mm of sludge, while the final settlement tank contained no measurable crust and approximately 150mm of sludge.

Twin Final Effluent Pump Chamber Service

The final stage of the system consists of a twin three-phase final effluent pump chamber fitted with two Lowara DOC7/A HS17 pumps.

Both pumps were removed from the chamber, cleaned and washed down before the impellers were inspected. No blockages were identified and both pumps were correctly re-seated and operationally tested.

• Pump 1 running current: 1.72A
• Pump 2 running current: 1.67A
• Pump alternation: Operating correctly
• Both impellers: Clear of blockages
• Both non-return valves: Operating correctly
• Isolation ball valve: Operating correctly
• Internal pipework: Good condition

Float Switches & High-Level Alarm

The pump chamber operates using four float switches: stop, duty, assist and high level.

All four floats were cleaned and individually tested, with correct operation confirmed. Pump alternation was also checked and the high-level beacon was successfully activated and tested.

No abnormal sludge or grease accumulation was present within the pump chamber and there was no evidence of surface-water infiltration at the time of inspection.

Complete Six-Monthly Service

During the visit, the grease trap, sewage treatment plant and final effluent pump chamber were all serviced as part of the site's scheduled maintenance programme.

• Grease trap high-oil alarm probe cleaned and tested
• Grease trap outlet filter cleaned and refitted
• Becker blower intake filter replaced
• Blower electrically tested
• Diffusers individually scoured and cleaned
• Loss-of-pressure alarm tested
• Solenoid valve and timers tested
• Final effluent quality and turbidity checked
• Both Lowara pumps removed, cleaned and inspected
• All four pump control floats cleaned and tested
• Both non-return valves tested
• Isolation valve tested
• High-level beacon tested

The complete wastewater treatment system was left operating correctly following the service.

Commercial Sewage Treatment Plant Maintenance

Continuing with six-monthly servicing allows the grease trap, sewage treatment plant and final effluent pump chamber to be routinely inspected and maintained as one complete system.

Regular preventative maintenance also allows developing mechanical, electrical and treatment-process issues to be identified before they result in breakdowns or deterioration in treatment performance.

We provide commercial sewage treatment plant, grease trap and pump chamber servicing across Forfar and throughout Scotland.