275 Upflow Biofilter

Our 275 Upflow Biofilter is a low-cost, highly effective stormwater filtration system that integrates with both downspouts and pump n' treats process systems. Flow rates for our 275 BioUP biofilters reach up to 65 GPM with a sweet operating spot for maximum efficiency at 30 GPM.

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Proven to Remove up to 99.7% of Metals

Explore our case study of a major semiconductor manufacturer and review the third-party lab results.

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The Upflow Solution

The heart of our treatment process lies with our gravity-based, dual-stage, upflow Biofilters. They use organic, carbon-negative media to strip out the stormwater contaminants. The biochar media strips the total/dissolved metals, BOD, COD, and a limited amount of nutrients from the stormwater.

Stage One- Filtration

The first stage is a container consisting of a filter bag made of an industrial grade 10 oz geotextile. There is a secondary filter screen located at the 1st stage filter container outlet – designed to trap any suspended solids that could potentially bypass the main filter bag.

Stage Two- Metals Removal

In the second stage of treatment, the stormwater is redistributed evenly across the second stage and flows upwards through the biochar media. This media treats the stormwater through adsorption, ion exchange, complexing, biological, and chelating in an upflow process. The biochar media strips out the total/dissolved metals, BOD, COD, and a limited amount of nutrients from the stormwater.

Why us?

Easy to Site

Gullywasher's 275 Upflow Biofilter consists of 2 stacked 275 gallon totes maximizing the use of space. The filter is highly portable and can be assembled in day.

Easy to Service

Gullywasher Biofilters are built with service in mind. There are no specialized tools needed to service any part of this BioFilter.

Easy to Maintain

Gullywasher's Upflow Filter Solutions use a removable insert that can be washed and re-used.

Biofilter Applications


Gullywasher upflow biofilters can be easily located at the end of the downspout to treat your hot spots, catching contaminants off metal roofs before they hit the ground.

Pump N’ Treat Applications

We can collect the rain-water via sumps and catch basins and pump the water to this system.

We can utilize virtually any filter media; however, the lab test results are focused solely on the use of filter-grade biochar. Third-party lab results have shown 99.7% removal of metals over a year’s service.

Flow Capacity
Max Treated
65 gpm
Ideal Treatment
20-30 gpm
50 gpm
1st Stage
1st Filter
10-oz geotextile
2nd Filter
Open Cell Filter Cloth
2nd Stage
Open Cell Filter Cloth
Organic Media
Amount of Media
20 cu. ft.
Filtered Collection
BioChar Mix 2
23.75 ft3
Filter-Grade Quartz Sand
7 ft3

Biofilters on the Brain?

Us too! Reach out and connect with us to talk about your business needs and how our biofilters can help you meet your compliance needs without breaking the bank.