Erosion Control March/April 2017 : Page 51

deficiency is, I can cite them for that. My approach has been, rather than to cite them and cause a lot of anxiety on the part of contractors, to educate them in the proper use of the correct BMP, so the problems don’t begin to start with. “Within Chamblee, contractors say I’m their worst enemy. Outside Cham-blee, I’m their best friend, and yet I teach the same thing coming and going.” Spotts notes that one significant problem is that the judicial system does not place as much importance on envi-ronmental crimes as it does others. “Although the federal government allows a very high penalty for viola-tions of the NPDES program, most city, county, and municipal judges treat this as a minor offense and don’t put a serious value on the monetary fines,” he says. “The result is that some contrac-tors laugh as they go out the door. They pay the check to the clerk and keep on going, and they haven’t even bothered to correct the problem on the site. I really have a problem with that.” Spotts contends that field inspec-tors could be much more effective if they knew they had the backup of the judicial system to enforce the laws and stress the importance of contractors abiding by the rules. Although Spotts is satisfied with the performance of the Silt-Saver devices, he says the state of Georgia is always on the lookout for new devices as well. “We in Georgia have a manual of the acceptable best management practices. I have a problem with the word ‘best’ because yesterday’s best is not the same as today’s best. It’s an evolving process to develop new products. “Roger has hit on a real gold mine here with the Silt-Saver, so my hat is off to him. He has made significant improvements in the program. I can’t tell you how many hundreds of those things I see almost on a daily basis as I go from one site to another.” Redmond Way Regional Stormwater Treatment Facility The Redmond Way Regional Storm-water Treatment Facility in Redmond, WA, has installed more than a thou-sand filter cartridges to address pol-luted runoff. It’s all part of an effort by the city to improve the quality of the water flowing from city streets into the MARCH/APRIL 2017 Sammamish River. Redmond recently adopted a federal permit for stormwater discharge to improve environmental protection and comply with federal and state laws. Con-ditions of the permit require the city to enhance efforts to clean the stormwater before it gets to local water bodies. City officials had worked with the Washington State Department of Ecol-ogy to develop a plan for constructing regional facilities complying with the city’s permit and the state’s stormwater management guidance manual. The construction of the regional facilities is funded by the stormwater capital improvement program, with support from developers and state grants. The city’s regional stormwater facili-ties plan utilizes regional stormwater facilities to meet its water-quality goals, support new development required by the Growth Management Act, and do so in a cost-effective manner. Regional stormwater controls are facilities designed to manage storm-water runoff from multiple projects or properties through a city-sponsored program in which individual proper-ties may assist in the financing of the facility, and the requirement for onsite controls is either eliminated or reduced. In Redmond, developers can pay a fee in lieu of constructing onsite facilities. Oldcastle Precast’s Perk Filter Media Filtration Device is cartridge filtra-tion designed to remove and retain pollutants from stormwater runoff. It can be used with a variety of different media to address site-specific pollut-ants of concern. The Perk Filter system captures sediment, metals, nutrients, and petroleum hydrocarbons, as well as gross solids and trash, to signifi-cantly reduce the total pollutant load in stormwater runoff. Standard cartridge heights are 12 inches and 18 inches. The 24-and 30-inch cartridges use modular stacks. PerkFilter Media Filtration is designed for flexible configurations that can be applied in vaults, man-holes, and catch basins with variable inlet and outlet locations, to provide high-efficiency treatment in a compact footprint. Field and lab tests show total phosphorous removal of more than 60% and total suspended solids removal of more than 80%. A pretreatment chamber is designed to prolong media lifespan by removing gross pollutants. The modular cartridge construc-tion design provides for efficient media replacement and cartridge handling. An integrated bypass system reduces construction costs by eliminating the need for a separate bypass structure. From October to December 2014, some 1,068 Perk Filter cartridges mea-suring 12 and 18 inches were installed at the Redmond Way Regional Storm-water Treatment Facility. They were stacked with the 18-inch units on the bottom and the 12-inch units on top to form 534 stacks to provide a treatment flow rate of 9,078 gallons per minute. The vault containing the stacks is 16 feet by 213 feet. Chris Demarest, product develop-ment manager for Oldcastle Stormwater Solutions, says, “The system removes total suspended solids, trash and debris, nitrogen, phosphorus, metals, hydro-carbons, and other pollutants.” He adds that typically, stormwater treatment units have been installed on a project-by-project basis. This system and other large regional systems in Redmond are designed so that not all individual properties must treat their own stormwater onsite, which reduces the constraints develop-ers have when designing their projects, says Demarest, adding that unlike installations that treat runoff onsite on individual lots, this unit treats runoff from a region of the city. Demarest says the Perk Filter was chosen “because of its high pollutant removal capabilities, its high treatment flow rates, its innovative design, and its value.” The system is being maintained annually. The maintenance cycle for the system can be modified based on the pollutant loading. The system has a turbidity meter installed for monitoring the influent and effluent. The use of the Perk Filter fits into the city’s overall stormwater manage-ment program as a matter of compli-ance with its stormwater permit, as it is a Washington Department of Ecology-approved manufactured stormwater treatment device. EC Carol Brzozowski writes on erosion and technology. EROSION CONTROL 51

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