As many sites under construction come up against space constraints for their water treatment, a new alternative is now being used for sediment control.
Sediment control ponds can be ineffective on small particle sizes, and sediment control ponds often need to be moved or eliminated during the course of construction to make way for in-ground utilities and other civil works. While mechanical ‘pump-and-treat’ systems are available using a combination of flocculants and sand filtration media to treat the site’s water, they are often quite expensive.
A new water treatment alternative that is being used very successfully on many construction sites now is the combination of a Tigerfloc Torpedo that is placed inside of a small mixing tube, which then empties out into a micro-pored dewatering bag. The Tigerfloc Torpedo and dewatering bag combination work well almost immediately; however, this new system really begins to shine after a few days when the dewatering bag begins to hold back enough sediment to allow it to swell up like a pillow and filter out most of the sediment from the discharge water.
The Tigerfloc Torpedo and dewatering bag combination has proven useful in all soil types: sand, silts, and even clays. After having passed through the Tigerfloc Torpedo and dewatering bag system, incoming water measured at >1000 NTUs dropped to under 25 NTUs once the system had been running for several days. Results are obtained of dropping the water turbidity by 50-100 NTUs immediately when the system is first turned on. Another option on sites that already have a sediment control pond (which still exceeds the allowable discharge limits), is to re-circulate the pond’s water through the Tigerfloc Torpedo and dewatering bag system and then empty the clean water into the sediment control pond prior to it discharging down the drain pipe. By re-circulating the water through the Tigerfloc Torpedo and dewatering bag system, it helps speed-up the process of sedimentation.
The Tigerfloc Torpedo and dewatering bag system is extremely effective, has a small footprint on site (approximately 20’ x 20’), and is much cheaper than other alternatives which may compete with these results. It is something to think about the next time you have a site where there might not be enough space for a sediment pond, and you don’t require something as heavy-duty (or as expensive) as a mechanical ‘pump-and-treat’ system.
