• Widening Interstate 10 to six lanes between Davis Highway (Exit 13) and U.S. Highway 29 (Exit 10); and, widening I-110 to six lanes between the Interstate 10/110 interchange and the Airport Boulevard overpass.
• Replacement of the Interstate 10/Escambia Bay Bridge that was destroyed in 2004 by Hurricane Ivan.
• Widening Interstate 110 to six lanes between the Airport Boulevard overpass and Maxwell Street.
• Construction of a new Interstate 110 interchange at Airport Boulevard.

Throughout the construction site, the project has had to work on several very large storm water collection ponds. The storm water collection ponds needed to be dewatered to retain storage capacity for future rain events. 
 
Mobile filtration systems, provided by Rain for Rent, were extremely successful throughout this large construction project. Using a product called StormKlear the systems were able to easily meet the Florida NTU turbidity requirements. The requirements state discharge cannot exceed 29 NTUs over background waters. Background historically is around 5 NTUs in this part of the state. The panhandle of Florida receives some of the state’s highest rainfall averages, the project expected to receive around 60” annually.
 
Archer Western, the contractor for the project, called in the services of Rain for Rent to build the mobile treatment. Rain for Rent incorporated several sand filtration systems and recommended the use of the StormKlear product in their systems because of the success they had with the product on projects in both Maryland and Washington.
 
Starting in February of 2008, Archer Western began running 2 multi-pod sand filter systems to dewater a 16 acre stormwater collection pond. The systems were required throughout the ‘wet season’ (spring, summer and fall). Each treatment systems were capable of treating a 1,000 gpm, but average flow rates were around 700 gpm per system. Total water treated is estimated to be around 150 million gallons of stormwater.
 
The nature of the material keep it in suspension, thus Rain for Rent choose the biopolymer GelFloc product which is made from crustaceans shells, a waste product of the seafood industry. Because of its performance with sand filtration and its ability to field detect against residual polymer, the Rain for Rent system met the contractors needs.
 
Starting NTU in the ponds fluctuated between 75 and 400 NTUs depending on rainfall and pond water level. Discharge was between 0.5 and 28 NTU with average discharge between 5 and 10 NTUs. Turbidity was taken manually 3 to 4 times per day or if any significant change occurred. Photo 1 below shows the suction float where the inlet water is drawn into the pump for filtration. The road construction project is located just beyond the pond.
Photo 1
 
Part of the pond was being filled in as required by the construction project. However the smaller storage capacity then required that the systems need to treat water more often.
 
Photo 2 below, shows the largest pond, 16 acres in size. The construction in the foreground shows how the pond is being filled in to reduce its size. The discharge from this pond averaged between 5-10 NTUs at 700-1500 gpm.
Photo 2
 
 
Rain for Rent provided mobile treatment systems and equipment which were staged on dams between the ponds (Photo 3 and Photo 4). 
Photo 3
Photo 4
 
 
4-pod sand filtration systems which used the GelFloc as a filter aid.
Photo 5
 
Photo 5 shows the filtration system viewed from the discharge point. 
 
The particles that caused the turbidity were very small and didn’t want to settle out with gravity. The GelFloc aided the systems by floccing the small particles together so the sand filters could remove. Because the GelFloc is biodegradable, there was not a concern of bioaccumulation.
 
 
Photo 6 below shows the discharge area. This is the point at which samples are taken of the discharge for NTU measurement and occasionally pH levels. Testing for free residual chitosan is also tested here using the StormKlear Residual Chitosan kit, designed to make on-site measuring easier and ensure compliance.
Photo 6
 
Photo 7 & 8 below show the discharge into the creek which drains into the stream and a close up of the water clarity at the point of the discharge pipe. 
Photo 7
Photo 8
 
The third pond on the site is an alum treatment pond. The DOT originally specified alum and pays the contractor to use the 2 pallets that were delivered on site. Alum is stored under plastic in photo 4. Alum drops pH levels below acceptable and pH has been raised before batch discharge can occur. Alum is only allowed in batch treatment. However the contractor has stated that the with the needed pH adjusters, the alum system is not nearly as inexpensive as originally specified.