Unlike wastewater, which flows to a treatment plant, stormwater in many areas flows to waterways without any additional treatment. Discharges often include pathogens, nutrients, surfactants, and various toxic pollutants. Since the National Pollutant Discharge Elimination System (NPDES) Phase II went into effect in 2003, smaller municipalities and private concerns have been required to have greater control of stormwater runoff. The response to the regulation has meant a burgeoning and highly competitive trade in products designed to capture and treat pollutants, improve the ease of installation, and allow for cost-effective maintenance. The best management practices (BMPs) used for the purpose include filter protection devices and catch basin inserts.
Paying Attention After BMPs Are Installed
Flooding, which occurs when an excessive volume of runoff is generated, causes more damage to property and infrastructure than any other weather hazard. Annual property damage estimates range in the billions of dollars. Reducing flooding is an ongoing challenge for many municipalities. In addition to flooding, some areas face additional issues posed by cold weather.
Jennifer Gadzala is the MS4 [municipal separate storm sewer system] operator for the town of Chesterton, IN, in the northwest section of the state. Cold-weather areas face a different set of challenges, according to Gadzala. “No product works best at every time of year. They are all site-dependent. In January, we had over 12 inches of snowfall in a single day. Then it melted in one day and we had an inch of rain. Every BMP was overwhelmed with flooding and runoff. Even structural BMPs suffer.”
Maintenance needs also vary from area to area, according to Gadzala, who describes a site in Chesterton that had highly erodible soil. “Sediment-laden water was jumping curbs and heading toward inlets. The developer first tried laying filter fabric under the inlet grates, but they became clogged with sediment, resulting in ponding and flooding roads.”
Blocksom filters were installed in October 2007, but by March they had not been maintained. “They were never cleaned, and they were clogged with mud,” Gadzala says. Blocksom suggests removing the grate with the attached filter, then cleaning it before putting it back on.
“Maintenance needs depend on the site,” Gadzala says. “You have to look at the filters to see how overburdened they are. If there is sediment around the sides, a shovel will work; if they’re smothered in mud, you have to take them off and clean them. These particular filters went through a winter of numerous snowfall events and were hit several times by snowplows.”
Maintenance falls on an owner or developer, Gadzala says, emphasizing that no filter is dependable during the winter months without continued maintenance. “The cold-weather states are a different world from the warm states when it comes to certain sediment control products.”
Steve Ovsak is project superintendent on a stormwater relief project being completed by Ruby-Collins Inc. of Atlanta. The project, in the historic district of Savannah, GA, involves replacing the old storm drainage system with larger-capacity pipes to relieve flooding in the adjacent areas of Alice and Tattanall Streets. Installation includes 6,100 feet of reinforced concrete pipe, 36 storm manholes, 56 curb inlets, more than 1,100 feet of sanitary sewer pipe, and seven sanitary sewer manholes. The reinforced concrete pipe mainline starts at 54 inches downstream on Montgomery Street and proceeds to 18 feet upstream at the Chatham Square area. The project, begun in January 2008, is estimated to take just over a year.
According to Ovsak, flooding has been a problem in the district for at least 150 years. The first two phases of this project involved building a microtunnel, or trunk line, to carry water from the street to the Springfield Canal and then into the Savannah River. “The old system was undersized, old, and decrepit,” he says.
Ovsak, who has been in the construction business for 15 years, says this is the first time he has used Silt-Saver products to protect an inlet. The reusable Silt-Saver devices have HDPE frames that fit over the inlets and are covered with filter fabric. “The normal coconut [coir-fiber] sock, you threw away, but this one can be washed and reused. The rock bags get run over and aren’t used anymore.”
Monitoring is an ongoing process for Ovsak. “I take a sample after every major rainfall. The results are that good: water quality is maintained at or below the original sampling.”
Decreasing the incidence of flooding has many positive benefits, including reducing auto accidents and traffic congestion and improving insurance rates in areas likely to experience street and property damage. And protecting inlets from pollution results in cleaner and healthier water sources for everyone.
As superintendent of a yearlong project to replace 16 blocks of street in Rawlins, WY, Kenny Bartels has had to worry about keeping polluted water from entering drains in an area that on June 14, 2008, experienced what he calls a “40-minute blizzard.”
“One advantage to the cold is that there is less water flow when temperatures are freezing,” Bartels says. He has found Blocksom filters effective for this project. “You just take them off and rinse them. They can take tremendous amounts before plugging.”
Bartels says that he has used silt fences on projects in South Dakota and has found them much less effective than Blocksom’s mats. “They plugged up so bad; these are easy to use. You just lay them over where the water is going. They’re small, a 5- by 6-foot mat, and one man can easily lift one for cleaning.”
In this case, a state highway running through a city, local area crews will be responsible for maintenance.
Bartels says that the state EPA monitors the effluent. “They take what they see coming out at face value. As long as they see an honest effort.”
A Curb Inlet Filter protects an existing inlet.
Ocean Views Bring Tourists—and Trash
Cities located near an ocean face particular challenges when managing stormwater runoff. Beachfronts and harbors face continual traffic, both maritime and human, and all of these elements lead to pollution of the waterways. Frequent cleanout of inlet filters and catch basins becomes a matter of time and money.
Eric Sanford of DDC Engineers Inc. is director of municipal services in Myrtle Beach, SC. Since adopting a single Snout-an oil-water-debris separator-at a stormwater convention from T. J. Mullins of Best Management Products several years ago, he has installed between 80 and 100 of the little beasts in the downtown area alone. “I just loaded one into my truck and took it home.”
The Snouts serve as the first line of defense in a beach area where people come to play hard and don’t spend much time picking up after themselves.
“We use Snouts at a point source to filter gross pollutants such as cigarette butts and trash,” Sanford says. “We get up to a million tourists a day along the Grand Strand coast here in the summer, and people are pigs.”
He has used the snout in tandem with other BMPs such as catch basin inserts and oil booms. “Most of this area was developed in the ’50s, and everything would discharge directly to the beach,” Sanford says. “The discharge pipes stopped at the dune and then washed into sand gullies to the water’s edge.”
The Snouts are inserted into existing catch basins, where they filter sediment, leaves, and other debris. “For the money, they’re a cheap BMP,” Sanford says. “For their dollar value, they are one of the better BMPs. They stand the test of time and are easy to install as a retrofit.”
Sanford says that the Snouts catch 75 to 80% of the pollutants. “We use these when size dictates; they’re a source treatment BMP.”
Since NPDES Phase II went into effect, storm drains have become a more prominent concern. “For the last 100 years, people in the United States have worried about water and sewer, not storm drains,” Sanford says. “The storm drainage industry and mentality have come a long way in the last five to 10 years.”
Sanford says that dealing with stormwater runoff has become a major priority for the 50-mile Grand Strand area that comprises the oceanfront, and
A Snout is used in a catch basin to filter gross pollutants.
right now the biggest effort is in storm drainage. “Once we lose the beach, we lose everything.”
While acknowledging that the Snout is not the answer to every problem, Sanford retains his loyalty to the adoptee. “There is no magic bullet, but [this solution] is stupid-simple.”
Easy maintenance resulting in lower labor costs becomes a high priority in any project requiring multiple applications. Chris Bellucci is the project engineer for the Department of Environmental Protection at Lemon Creek on Staten Island in New York.
“We’re making all new stormwater collection areas in order to send the water to retention basins instead of releasing it directly into creeks, rivers, and the ocean,” Bellucci says. One of the tools he’s using is a Blocksom inlet filter. “They work great; they are easy to change. You just cut off the old wires like zip ties and reattach new pieces. Previously, New York had to have the old standard filter fabric with stone on top. Those were hard to clean, because you had to remove the top and take it apart, then put on new material.”
Bellucci says maintenance is easy with the new filters. “I can just send a guy to sweep off the dirt and debris or scoop it with a shovel. If the filter rips or tears, we can just put in a new piece.”
Installation is quick and efficient. “It’s just a woven fiber zip-tied to the top of a catch basin grate.”
Jose Casio, a stormwater engineer for the city of North Miami Beach, says that the BMP Snout baffle is the required baffle for the city’s public works projects. Currently working on the Hanford Boulevard (Downtown) Projects, a roadway and drainage improvement project, the City of North Miami Beach Public Stormwater Division is a big fan of the BMP Snout baffle. “It is durable and long-lasting, much stronger than other baffles currently in the market.”
Casio says that the BMP Snout baffle may cost a little bit more than some of its competitors, but it is worth the cost in the long run. “If a regular baffle is damaged, it can involve cutting roadway pavement, excavation, and restoration, which makes it expensive to replace.”
For Casio, the Snout’s other advantage is its clean-out port. “For maintenance, you just take it out and access the French drain pipe for cleaning. Just open, insert the hose, and flush.”
Long Beach, CA, a city with a population of over 461,500, is the fifth largest city in California. The Port of Long Beach handles the most cargo tonnage of any port on the West Coast. And every year, approximately 5 million people bask in Long Beach’s 345 days of sunshine.
The city’s commitment to balancing environmental quality with the obvious economic benefits of port activity is reflected in Healthy Harbor Long Beach, an initiative aimed at enhancing air quality, water quality, and wildlife habitats.
According to the city’s Web site, the Harbor Department has dug up contaminated sediment from the harbor bottom and buried it in land created for new port terminals. This innovative reuse earned the port the Environmental Hero Award from the EPA. In addition, the Harbor Department has launched a stormwater pollution prevention initiative. Tenants are trained in pollution-fighting practices such as using drip pans to catch engine oil, sweeping sites frequently, and sampling and analyzing stormwater runoff. The California EPA has honored the Harbor Department for this program.
Tom Leary is a stormwater program officer for the Long Beach Department of Public Works’ Stormwater Management Division. He says that the city is using a variety of methods to treat stormwater runoff. Some of these are pollution prevention and education, enforcement, source reduction, control devices (clarifiers), street sweeping, standard urban stormwater mitigation plans (SUSMPs), and the California Environmental Quality Act compliance.
Long Beach is using AbTech’s Smart Sponge technology in catch basins whose tributary drainage is recreational waters. “In addition to successfully addressing the targeted pollutant-bacteria-the units also capture grease, sediment, and trash with no compromise to the flood control system,” Leary says. “The great thing about the AbTech inserts is they sit inside the catch basins and are easily accessible from the street, making maintenance quick and easy.”
Smart Sponge units capture bacteria, grease, sediment, and
trash with no compromise to the flood control system.
Maintenance Takes Center Stage on Construction Sites
Any construction area poses constant challenges for stormwater maintenance. George Sholy, president of S & S Landscaping in Fargo, ND, describes a recent job for General Contractors Master Construction on 52nd Avenue in Fargo that involved placing inlet protection devices at various phases of road reconstruction. “This is an expanding part of town where they are changing the road from two to four lanes and adding new underground sewer and water lines,” Sholy explains.
The initial phase of the project involved placing straw wattles around existing inlets and in ditch bottoms. Once the roadway was removed and new pipes were installed, the inlets were switched to another type and Dandy Sacks, from Dandy Products of Westerville, OH, were added to filter debris. “The Dandy Sack fits the inlet and hangs below the grate to filter sediment,” Sholy says. “After each event, we check to see if it is plugged, then we clean it or replace it. It’s reusable, and, usually, we can use it a few times.”
In 2008, it rained in Fargo every other day for the first two weeks of June, according to Sholy. “The rain held up the project for a while, and we had to change the filters more often. We were called out several times to unplug them and get rid of the debris.”
After the paving process, the crew seeded and sodded along the roadways, using hydromulch and adding straw wattles where needed. “Once the roadway was graded, we installed new inlet protection until the turf was established,” Sholy says.
Any runoff eventually goes into the nearby Red River, so the motivation is high to keep the effluent free of debris. Sholy has been pleased with the Dandy product. “It is easy to install, easy to maintain, and easy to clean. The Sack is also reusable. That’s why we like it.”
Steve Kesler, project superintendent for Shannon Strobel & Weaver of Auburn, AL, last year directed construction on a Super Wal-Mart in Covington, GA. While the actual building was finished ahead of schedule in 10 months, Kesler says he stayed around for another three months until the store was up and running in September 2007. One of Kesler’s concerns was to monitor the efficiency of inlet protection devices from Silt-Saver.
The stormwater pollution prevention plan (SWPPP) prepared by Wal-Mart engineers did not specify a particular product, only that some type of filters be placed in the inlets. Kesler says he opted instead for Silt-Saver’s silt fabric-wrapped unit that comes in one solid piece “shaped like an L” and fits over the inlet. “It doesn’t break down like the blocks do. It is easier to clean and handle and fits over the curve of the inlet itself.”
The project also utilized Silt-Saver’s plastic domes to cover manhole inlets. “Wal-Mart’s minimum requirement was a silt fence using two by fours. Silt-Saver’s filter fabric goes over a plastic dome that sits down over the hole. When rainwater runs to the hole, it filters the sediment. You just take the cover off the dome, clean it, and return it. It’s easier to work with than the two-by-four fence and it’s more efficient cost-wise.”
Big things are underway in Idaho Falls, ID. In June 2007, developer Ball Ventures began work on a 400-acre planned community along the banks of the Snake River. The project includes housing, offices, shops, restaurants, and parks.
John Gregory, manager of Specialty Construction Supply, which sells, installs, and maintains erosion control materials, says the 3-mile-long area is a high-profile job for his company. “It’s right on the Snake River, and HK Contractors are very vigilant in their applications to prevent silt and sediment from entering the river.”
To protect the river during the long construction phase of this project, Gregory’s company has been hired to install products that will keep out debris and filter the sediment that gets into the stormwater system. “We started in 2007 with silt fence installation; we use different products for every phase,” he says.
The company uses Dandy products such as Curb Sacks and Bags. If the inlets don’t have grates, the company uses straw wattles. Silt fences with straw wattles behind them are used to keep the dirt back along the length of the river.
Charles Fraga works for Gregory as water pollution control manager. “I’m the weekly inspector. I drive over after every rain to see if the devices are working.”
Apparently Dandy is living up to its name. “The Snake River is sensitive,” Gregory says, “and the products are doing a great job.”
Tripp Bishop is general manager for the construction division of ACF Environmental in Richmond, VA. He uses a variety of products, including the GutterGator, patented and distributed by ACF and used exclusively for curb inlet protection by Centex Homes, a Washington, DC-area builder of new homes.
“The GutterGator increases the flow of water, it’s easy to maintain, and you can take it out and power-wash it. You can reuse them until they break apart, allowing you to do maintenance at the road level rather than sucking the debris out of the storm sewer.”
The GutterGator, Bishop says, is lightweight and lets the water flow through a green mat, which is attached with Velcro to a stiff, high-density plastic backbone. “If the backbone breaks, say from a tractor tire, you can just remove the mat and reuse it. It’s a high-flow turf that won’t biodegrade or photodegrade.”
While the Gator seems ideal for curbs in a construction area, Bishop also gives high praise to the Erosion Eel from Friendly Environment, which he says is ideal for high-flow ditch lines and swaths. “I’ve used it as a check dam to slow water velocity. It will check the flow and slow erosion on the downstream side, so it both purifies and checks. It does a good job of segregating chemicals such as phosphorous and leaving impurities behind. Studies have shown that it gets out up to 95% of the impurities.”
But the best part of the Eel, according to Bishop, is its reusability. The 10-foot-long geotextile tube, about 10 to 11 inches in diameter and filled with recycled tire rubber, can simply be put down on the ground where needed and picked up and moved when a project is finished. “It’s costly,” Bishop says, “but it pays for itself on the first job, and you can use it again.”
Fabco Industries of Jericho, NY, supplies two models of drain inlet filtering inserts that are targeted towards erosion or sediment control. The StormSack and the StormSok each consist of a mounting system together with a replaceable woven geotextile filtering bag. They feature lifting tabs for easy cleanout, plastic mesh bag liners to protect the geotextile material during cleanout, and a can fitted with an optional absorbent boom to capture oils and grease. “This boom is a popular option here on Long Island where the bags are used as pre-filters to larger BMPs,” says Fabco’s John Markee.
Markee says that the bags are used in Nassau County, NY, in large land-based infiltration areas. He says the majority of customers use catch basin inserts in areas that have really no other protection, such as urban areas where property is scarce and expensive. He says the customers using filtering insert units are purchasing StormBasin and StormPod; and while these are effective on sediments, if that is to be the primary use, he suggests StormSack or StormSok instead.
“Speaking from our own experience, which is focused here on Long Island, NY, and the surrounding states of New Jersey and Connecticut, these agencies select filtering cartridges that treat for pathogens and nutrients. This is because of the high number of bathing beaches located in villages like Great Neck, Smithtown, and Freeport. They have installed these near affected water bodies. The town of Huntington is trying them at two beaches.”
Markee recommends cleaning catch basins about three times a year. “In most cases they can be cleaned out in 10 minutes or less. Modern sweepers can be equipped with catch basin cleaning wands, and the sweeping itself reduces materials than can collect. When the basins do need cleaning, the same crew and piece of equipment can handle the job.”
End users generally agree that “there is no magic bullet” when it comes to purchasing stormwater protection. The consensus seems to be that most of these products are easy to install, cost effective, and a whole lot more efficient than the piece of chicken wire topped with a brick that was often used in the old days.
