Sustainable Drainage System Design and Implementation

Sustainable Drainage Design and Implementation

 

By Ankit Sehgal

 

 

Sustainable drainage and water treatment design has been a school of thought that has been slowly turning into applicable practice. It is no longer a concept of the future, it's happening now.

 

The idea of the reclamation and reuse of grey water, applicable to LEED pre formed linear drainage systems has been a topic of conversation that has been resonating in recent years. We began our framework last year and touched on the topic here.

 

Swiftdrain received a call recently from Angelozzi Precast. AP is in the process of reconstructing and adding additions to a pre existing, multi million dollar, state of the art, fine terrazzo manufacturing facility.

 

Granite and Terrazo are fine stones used as marble tiles and in and around the home. There is a lot of cutting and sawing involved to make custom granite. It takes a lot of precision and a lot of technical skill to be able to read a plan and cut it into life.

 

After a day of cutting, naturally the floor of a terrazzo manufacturing facility will be covered with soot and debris.

 

This soot and dust needs to be washed everyday after a days work or it can accumulate and cause a slip hazard. One doesn’t necessarily want to mop this soot, it can clump up and solidify.

 

So what we did was design a custom drainage system based on some particularly and initially challenging site conditions, site requirements, flow rates, logistics and time constraints.

 

 

Here is what we came up with:

 

The design: Perimeter

 

Trench-Drain-Corner-Right-Angle

Corners are mitered on site

 

There are a few things we explore while envisioning a drainage system for a technical manufacturing facility like this one.

 

During the lifespan of a project which can last several years from initial design and conception to installation,  It’s not uncommon to get a call to discuss specifics or instaltion details from the same project and person, every day, for an hour for weeks on end until it ends. I only mention that because the time constraint on this project was initially challenging. This project was successfully executed in under 10 days.

 

Physical Layout:

 

AP was in the process of importing a custom several hundred thousand dollar terrazzo machine from Italy and needed to furnish a drainage system to efficiently capture and convey the surrounding water, wash down, cement, “muck” and water effectively.

 

Constriants: Shallow depth restrictions. The site did not allow for depths deeper than 15"

 

 

The physical layout: The layout we came up with is custom. It can be best described as a perimter drainage system with one T junction and 4 90 degree angles with an invert evacuation and max flow potential.

 

 

On CAD the design looks like this:

 

trench-drain-corner-miter

Corners are miters on site to form perimeter trench drains

 

The interesting thing about this project was the T junction and 4 90 degree angles. In this line of work that is one of the most difficult and challenging on site construction drainage techniques there are. I spend weeks to months at a time teaching and going over this technique to contractors, customers, engineers and all customers alike. The right angle takes skill. The T junction takes an incredible amount of skill, know how and experience. To be able to furnish this drainage system is one thing, to be able to install it to specification is another, to be able to adapt and change on the fly can only be done when the contractor installing it is as equipped in executing my drainage plans. I can come up with the best plans, design and physical product, but it means nothing if I cant efficiently convey how to install it on site. Esepcially, when its wildy technical.

 

 

The thing is, is that these cuts can be made by most seasoned contractors. They aren’t challenging for folks building airports or chemical processing facilltiies. But the perception of the T junction is an obstacle. From time to time, one of my jobs is to effectrivley convey how to make this junction and teach them how to do it. It always gets done, but it takes time.

 

perimter-trench-drain-concrete-encasement

Ready for concrete

 

Time Cosntraints: It takes time to configure each system, gather all the parts, pack them, itemize them, organize them and strap them on pallets to get them ready to ship out. Each unit weighs 250 lbs and we used 32 units to make this system complete. Supply chain shortages due to the pandemic pose its own set of intellectual challenges. This was accomplished by forward thinking and picking up the pace.

 

 

The physical considerations we came up with:

 

Floor Square Footage:

 

 

Expected Inflow:

 

 

Expected inflow is the rate at which water enters the pipes of the system. We don’t want to overwhelm the system nor do we want any backflow. The muck generated by the granite manafturing process is akin to plaque. It needs to be effectively be conveyed to the exit point. This can be done by sloping each foot of the pipe a certain percent. This was a custom slope we devised.

 

 

 

Expected Load Requirements: Heavy Duty Class E, Up to 75,000 lbs

 

Load Classification: Heavy Duty

 

Backflow:

 

No worries here

 

Invert:

No worries here

 

Right Angle:

 

Usually a huge learning curve

 

T Connection:

 

Very detailed and intricate, these guys figured it out in a couple days.

An end outlet is used to make a T connection

trench-drain-t-connection

Trench Drain T connection Miter

 

Time Constraints:

 

750K dollar Machine from Italy was coming in under 7 days, multi million dollar redevelopment site, the drainage system needed to be designed, configirgured and installed in under 7 days. Folks don’t realize most companies take 4 weeks to ship. We can do 3-5 days shipping because our process involves solving fast and slow and staying lean.

 

 

Installation Ease:

Right angles, T junctions and Mitering bends can cause some challenges. With the 200 series and proper installation guidance. This project was completed successfully as the one of the first fully autonomous sustainable drainage systems in the State of New Jersey.

 

LEED: