TrenchFormer FirstFlush®

Stormwater Filtration for Urban Runoff

The "first flush effect" refers to the initial surface runoff during a rainstorm and the resulting surge of concentrated water pollution. Corresponding high sheet flows wash the pollutants through storm sewers to local surface waters. Our engineers created a Best Management Practice (BMP) to counter the negative effects of urban runoff.

Any filtration system will collect debris, capture hydrocarbons, and should reduce pollutants. Our solution also manages the significant overland flow during initial runoff events. We prioritize the treatment of a first flush event by allowing prolonged rainfall to bypass the treatment media. This bypass minimizes pulsing and prevents concentrated pollutants from the "first flush effect" from continuing on to downstream waterways.

FirstFlush® is the perfect solution to meet this critical stormwater filtration challenge.

TrenchFormer FirstFlush
Sediment Screen Filter Panels Outlet Connections Removable Solid Cover Engineered Slope Structural Frame

Sediment Screen

The stainless steel sediment screen captures solid debris in the first chamber.

Filter Panels

Stainless-steel filter panels are designed to accept project-specific filter media packs.  Filter packages can be removed and replaced quickly for easy maintenance.

Outlet Connections

EPS forming system allows the installation of practically any fitting required to connect the pretreatment system to sanitary sewer or stormwater piping.

Removable Solid Cover

Solid covers are seated on independently anchored frames and removable for ease of access and maintenance.

Engineered Slope

The pre-sloped bottom eliminates ponding.  A critical consideration on projects where vector control is a concern.

Structural Frame

Structural steel angle is independently anchored to maximize load transference into the encasement concrete.

BMP SOLUTION

POLLUTION PROBLEM SOLVER

ABT Inc’s First Flush® products are designed specifically for sites under 100 acres where specific pollutants – oils, greases, and other hydrocarbons – must be captured without impeding bypass flow particularly during the first fifteen minutes of a rainfall or “first flush” effect.

Space restricted sites: First Flush technology is perfect for sites that lack the necessary area for retention ponds and larger structures.

STORMWATER FILTRATION

FILTRATION MEDIA

FirstFlush is the perfect solution when seeking a BMP that must handle sheet flow, control vectors, collect debris, treat bacteria, and capture hydrocarbons – all on the same site.  ABT First Flush systems utilize a variety of filtration media and fabrics.

  • Standard Filtration “Blankets”
  • Antimicrobial Filtration Media
  • Hydrocarbon Media
  • HMR – Heavy Metals Removal Media

 

1640FF Product Data – FirstFlush Stormwater Filtration Systems

The FirstFlush 1640FF, our largest capacity design, uses ABT’s patented forming technology to create a highly durable concrete component.  As effluent enters either through an inlet pipe or a trench drain, the first chamber captures solid debris.  After passing through the sediment screen, effluent passes through two removable smart sponge filter panels before exiting.  The pre-sloped bottom eliminates ponding, an excellent feature where vector control is an issue.  The 1640FF is provided with solid covers.


Description

Dims

(in)

Debri Volume

(cu. ft)

Bypass Flow Area – Debris Chamber

(in-sq)

Bypass Flow Area – Filter Chamber #1

(in-sq)

Bypass Flow Area – Filter Chamber #2

(in-sq)

Details Sheet

(.dwg .pdf)

Specification
(Coming Soon)

1640FF24-4

4′ Long

24 x 48 x 48
9.4
46.8
165.8
-NA-

1640FF24-6

6′ Long

48″ Depth

24 x 48 x 72
15.5
46.8
146.6
-NA-

1640FF24-6H

6′ Long

30″ Depth

24 x 30 x 72
9.5
42.5
146.6
-NA-

1640FF24-8

8′ Long

48″ Depth

24 x 48 x96
19.2
44.6
129.6
163.6

1640FF24-8H

8′ Long

30″ Depth

24 x 30 x 96
11.85
42.5
142.4
153.0