Mills Bunded

Complete redesign and implementation of a wastewater and rainwater management system for an unroofed, high-volume oil and equipment storage bund.

Mills operates a large bunded area dedicated to storing various oils and heavy equipment. By environmental standards, a bunded area must hold at least 110% of the largest tank’s volume to protect against major breakages, general leakage, or spills during servicing.

However, Mills faced two critical environmental and logistical hurdles:

1. High-Risk Rainwater Overflow: Because the height of the vats prevented the installation of a roof, the bund was completely exposed to the weather. During heavy rainfall, the area would fill rapidly, creating a severe risk of overflow and major environmental pollution.

2. No Town Sewage: The site lacked access to a municipal sewer system. All water from the bund had to discharge into a large evaporation pond, which strictly dictated that the treated water be of an exceptionally high quality.

In early 2020, Mills approached another company to resolve the rainwater issue. Unfortunately, the result was an expensive failure. The previous contractor simply installed a standard oil-water separator without any necessary pre-treatment.

The inadequate system was doomed from the start:

• It could not keep up with the volume of rainwater.

• Oils, dirt, and debris constantly blocked the pit, suction line, and the separator itself.

• The client suffered significant downtime and lost staff hours due to constant manual cleaning.

• The poorly designed system burned through approximately 15 replacement pumps.

Despite returning to the site, the previous contractor only offered to supply a larger standard separator, a solution that failed to address the root cause. Understandably nervous about further wasting money on ineffective solutions and facing potential environmental fines, Mills began searching for a company that genuinely cared about solving the problem.

After receiving overpriced and uninspired quotes from other suppliers, Mills reached out to GPS Environmental. Recognising the severity of the pollution risk and the client’s frustrations, we took a completely different approach.

We conducted a comprehensive site visit to properly diagnose the mechanical and environmental failures of the existing setup. Instead of offering a cookie-cutter product, we sat down with Mills to explain the exact mechanics of the issue and presented multiple viable, custom-engineered options. Our primary focus was designing a robust pre-treatment and separation system that would successfully handle heavy rainwater surges without burdening the client with exorbitant upfront costs or ongoing maintenance nightmares.

By prioritising transparent advice and expert engineering over a quick sale, GPS Environmental successfully restored the client’s trust. Mills is now extremely satisfied with the consultation process, and we are currently in the final stages of designing a customised, low-maintenance wastewater system that will permanently safeguard their site and the surrounding environment from pollution.