Save Time and Spare the Headache with the Proper Wastewater Pretreatment

Where to Turn When Traditional Methods Don’t Work

COVID has changed many aspects of daily life. One of the side effects, hidden to many but not those charged with wastewater treatment, is the increase in the types of trash hitting wastewater systems that defeat the usual methods of removal. The increase in these problematic waste streams clog up systems, creating havoc and headaches for those charged with wastewater treatment. Mack Industries can offer solutions for wastewater pretreatment that can help.

Trash Traps


Trash traps are an older but generally effective technology and the type that offers the most economical method of dealing with large bits of waste, especially for smaller wastewater treatment operations. The trash trap allows heavy solids to drop out and floating solids to rise to the top. Facilities often combine the trash trap with comminutors or macerators to grind the trash into smaller, more manageable bits. As long as the flow is regulated or managed properly, trash traps supply the level of performance required to avoid clogging up the system.

Rising Problems


However, items like plastics, rags and surface disinfectant wipes don’t sink or float—they stay in suspension and a trash trap doesn’t capture items in suspension. While surface disinfectant wipes aren’t a novel item, the pandemic has caused personal hygiene to ramp up to survival status, sparking a 17% spike in sales of surface disinfectant wipes from 2019 to 2020, according to a study by the Freedonia Group. And although not meant for sewage systems, many people flush these wipes, leading to the necessity of implementing alternative methods to screen them out.

Other “offenders” in the wastewater system include plastic bags, rags, and increasingly, adult diapers flushed into the system from nursing and retirement homes.

Pretreatment Screens


Screening is actually the best method of capturing waste and removes objects that remain in suspension in wastewater treatment plants that could clog downstream equipment such as pumps or pipes.

There are a few types of screening methods that require differing levels of labor to maintain.

A bar screen is non-mechanical and plugs up fairly quickly, requiring manual labor to clear.

Mack Industries recommends mechanical screening systems, which are basically self-cleaning. Among various options there is a spiral, drum, auger or static style screen. Price and application differentials help guide selection of the proper style screen for a given operation.

A spiral screen removes trash and unwanted solids to help the plant run more efficiently. An auger style screen results in more compact discharge and lowered disposal costs, while a drum screen is typically housed within its own building or unit.

Mack Makes Installation Simple


After the wastewater facility has obtained a permit from the appropriate local regulatory agency, Mack Industries can get to work. Once the best prescreening method is determined and measurements secured, our team builds the screen. Every aspect is prefabricated to make it a “plug and play” installation as much as possible.

The tank size dictates the piece of equipment possible for installation. Screening systems can fit a footprint of as small as 10’x20’, on up. The screen extends into a flow channel, angling upward and out of the tank to dump the screened garbage into a dumpster.

The new screening system has to bypass the pump flow to drop the new tank into place however with precast products fabricated by Mack Industries, the bypass cuts the traditional downtime from days to hours in most situations. The incoming sewer line depth is a critical factor in the placement and time required for a new screen installation.

Perfect Partners


While Mack Industries has experience working with almost any size operation, some facilities that have increasingly expressed interest and could benefit from a pretreatment screening system include:

  • Small municipalities

  • Mobile home parks

  • Campgrounds

  • Detention facilities

  • Nursing and retirement homes

Due to its precast products and experience, Mack Industries can offer quick turnaround times. The benefit of working with Mack is that each system is customized to the individual application space allotments and budget, rather than shopped from standard items in a catalogue. Mack Industries will typically pay a visit to the site, verify accurate measurements and design the system that will work at optimal efficiency for the best long-term solution and best return on investment.

Contact us any time of year — the precast products can be installed in any weather and don’t rely on ground temperature to set. The experts at Mack Industries are ready to help you solve your wastewater treatment headaches.