Mobile water or wastewater treatment equipment can provide an immediate solution to the problem of interrupted service.
Mobile units require a smaller commitment of resources for treatment, reduce operating costs and environmental footprint, and allow water projects to use a temporary solution before investing in a full-scale installation. Implementing mobile water or wastewater treatment solutions has become more popular as an accepted method of meeting challenging treatment needs, especially when the time frame for decision-making is limited.
Mobile, often containerized, skid-mounted units can be on-site within days, a distinct advantage over traditional installations. Set-up time is shorter, so operations can get back online quickly. A mobile water or wastewater treatment solution is also particularly appropriate for:
- Emerging operations where a plant is not yet installed, or equipment is not yet up and running
- Bridging the gap when determining how to fix or replace old equipment
- Providing for continued service during emergency situations
- Solving a temporary, project-based need, such as an ash pond closure
- Avoiding a larger, more permanent upgrade, as an alternative to the expense of an upgrade
- Focusing on the company’s core business by hiring someone else to run a less significant part of the operation
- Drawing costs from operations, rather than capital expenditure budgets
Making the decision to use mobile equipment involves installation and operations considerations. The units generally provide a contained, turnkey approach to the problem, but this doesn’t mean that customers do not have to be involved in the decision making for, and preparation and implementation of, the solution.
Choose a Problem-Specific Solution
To make the most effective decision, customers should enlist engineering expertise before ordering mobile equipment. Although a customer may enter a rental situation with a bias for a particular equipment choice, a more efficient approach is to get a full understanding of the problem.
As an example, at a mobile wastewater treatment site in the South, a customer requested a series of aeration tanks for the community’s wastewater plant. While the customer said the aeration tanks in series were needed to do the job, he didn’t mention that the location had an issue with heavy rains, nor that the rains could produce a wastewater stream that could overwhelm the tanks.
Ultimately, an event took place where a record amount of fall rainwater overwhelmed the entire system and washed away the system’s media. If a more accurate assessment of site conditions had been outlined initially, the supplier could have recommended a modification to the solution that would have protected the treatment train during times of heavy rain and met the outfall permit requirements.
Hiring a supplier with expertise in process and applications engineering helps determine the overall rental goals and how to best achieve them.
Expand the Mobile Experience to Provide a Complete Resolution
Mobile rental solutions present greater opportunities than do solutions that entail simply providing equipment. A facility can opt to have the rental supplier take care of the complete range of the solution, from installation to operations. This approach can improve a facility’s economic and environmental performance, allowing it to focus on its core business strength.
A model like this has worked well for a WesTech utility customer in the East. This customer has contracted with WesTech to remediate a coal ash pond to meet EPA regulations. WesTech developed the equipment process for the site, then handled testing and installation. WesTech is now running operations on-site. Equipment at the site includes a mobile RapiSand™ unit, pressure filters, a Chem Center, and ultrafiltration units.
This holistic solution combines design expertise with in-field service management. The operations will continue for months or even years until the ash pond is safely closed.
Consistent staff is critical for this approach to work – an on-site manager will know the operation and be able to quickly respond to any issues. Even in a conventional mobile water or wastewater treatment installation, service visits are most effective when made by people who know the project well. The proper service (and operations) team with extensive background knowledge can more effectively problem-solve with the client, minimizing field and labor time.
Process discussions are best when they take place before construction begins at the site.
Expect There to be Variations Between Mobile and Conventional Installations
Mobile wastewater treatment systems do not work exactly like full systems, so customers may need to modify expectations for operations.
For example, WesTech installed a rental clarifier at a Midwest refinery. The plant was planning for a full replacement installation of one of its clarifiers but hadn’t been able to bridge the gap between pulling the old one offline and installing the new one in the same footprint. The rental clarifier bridged that gap.
Once installed, the equipment can work differently than expected.
In this case, the rental clarifier was much shallower than the original one and had less underflow. The operator didn't realize that this would matter, so he operated it as if it were a conventional clarifier at full capacity. This caused immediate problems. WesTech engineers were on-site quickly to troubleshoot and diagnose the problem and optimize the installation. Once the operators were retrained to run the rental clarifier with adjustments for its smaller capacity, the rental installation was successful.
Address Treatment Needs in the Early Stages to Avoid Emergencies
Although mobile water and wastewater treatment solutions are effective for emergency use, making plans as early as possible can avoid unnecessary alarm.
The situation in a Western town is an example of what can happen when a decision is delayed. In the early 1980s, the owner of a mine turned off the pumps that kept the neighboring mine pit dry. The slowly rising, highly contaminated water in the pit had the potential of endangering the community below. Systems are in place to clean water and release it outside of the mine pit, but they are inadequate. The cost is far too high with the current system to keep it up for a long period of time. The town has been looking for a cost-effective solution to reduce the rise of the toxic water.
In the meantime, the mine stands uphill from the community, and if the water level exceeds the critical height, the community will be in jeopardy.
In this instance, a rental is a short-term solution that buys time while the long-term solution is being finalized. A rental system will be used to treat the mine water, pulling enough of it out of the pit, cleaning it, and then releasing it into a nearby creek so the immediate danger of contamination from too much water in the pit will be mitigated. In this situation, a quick, temporary mobile installation gives concerned parties more time to develop a permanent solution.
Engaging a mobile unit to meet a plant’s water and wastewater treatment needs has many advantages. It can be tailored to the specific time frame of the treatment, whether weeks, months, or years. It is also a cost-effective, quick alternative to a full installation. A rental fleet can be a creative solution to ensure uninterrupted water treatment in oftentimes difficult or unusual conditions.
Mobile units do operate differently than full installations. Having an informed approach to enlisting a mobile or rental unit can save time and headache in the end.