Stormwater Good Housekeeping: Prevention Worth a Pound of Cure
Of the six minimum control measures required under National Pollutant Discharge Elimination System (NPDES) Phase II permits, one, pollution prevention and good housekeeping, is intended to ensure municipal operations aren’t themselves contributing to nonpoint-source pollution. In addition to ensuring city vehicles, buildings, and storage and disposal areas–such as those for sand or salt in the winter–are maintained in such a way to minimize pollutants, good housekeeping practices can also refer to tasks such as street sweeping, cleaning out catch basins, and general maintenance of the storm sewer system.
In Hillsborough County, FL, both the county’s staff and outside contractors are used to keep the area streets clean. “It’s determined on a basis of availability,” explains Rick Luff, who works for the county. “Vacuum trucks are used to clean out basins. The Environmental Protection Commission, a state agency funded by the EPA, says the materials that wash off roads are toxic material; you have to do something with it. Now we have three “˜special mountains’ of this dirt, yet weeds are growing on it–that’s how toxic it is.” The county’s sweeping program includes four large sweepers, all Elgin Broom Bear model FL42H. These mechanical sweepers have large capacities–350 gallons of water and 4.5 cubic yards of debris–and a short wheelbase for maneuverability when cleaning a wide range of street widths.
“Traffic patterns were studied to determine how often each street must be cleaned,” Luff explains. “When it rains down here, it floods. Debris washes in and plugs drains, so we must keep them cleaned out as part of our maintenance programs.”
Debris is merely a symptom of what affects the stormwater system. “We’ve had lots of population growth here,” Luff says. “Our rural areas have become less rural; what once were swamps–natural areas for containing and processing rainwater–are now subdivisions.”
Owners of private property are responsible for their own storm basin cleanup. “The stormwater department doesn’t really check on private property to make sure owners are doing maintenance,” Luff notes. “Our code group, which makes sure the property is up to code standards, checks to ensure the structure is not rotting, for example.”
Warm temperatures and standing water can provide breeding grounds for mosquitoes. An efficient stormwater program works in concert with an aggressive mosquito control program to prevent proliferation of the insects. “The county does extensive spraying–from boats, trucks, and from the air,” Luff adds.
Because of its sandy soil, elevation, and weather patterns, Florida spends quite a bit of time dealing with water in one form or another. “When it rains, the water has to go somewhere,” Luff explains. “Florida’s not high above sea level, so we have to make sure the rainwater has somewhere to go. The natural swamps once took care of that problem, but now we have to take care of where rainwater can drain.
“Water, water everywhere–yet, we don’t have enough good drinking water,” he muses. “Either way, water is a big infrastructure issue for Florida.”
Scheduling Cleaning on the DOT
Farther up the coast, Delaware’s Department of Transportation (DelDOT) uses a variety of methods for street cleaning. “Some work is contracted out, other is kept in-house–it’s all a matter of the workload,” reports DelDOT’s North District engineer, Andy Bowman. “We can only do so much in-house. When work orders pile up to a certain level, we contract out.”
In addition to sweeping area streets, which include the Wilmington area, DelDOT cleans out catch basins with a flusher truck. The collected debris is dewatered and sent to a landfill. “We have an NPDES permit for Newcastle County, but we don’t do most of Wilmington; usually we do roads out of city, and our portion of the interstate highway. We sweep each road at least once a year at a certain frequency, which depends upon classification of the road, based on traffic counts.”
DelDOT’s NPDES group quantifies the benefits of good housekeeping practices and nonstructural BMPs, such as cleaning catch basins, cleaning out stormwater retention/detention ponds, street sweeping, and inspection of the infrastructure. “They look at BMPs and the benefits we get,” Bowman says. “They also present public education programs to convince citizens not to overwater their lawns or dump used motor oil down the storm drains. The NPDES group puts out flyers and does an inventory of our drainage system. After the inventory, the group marks the inlet with a sticker: “˜Only rain down the drain.'”
Delaware needs to protect several important watersheds, such as the Delaware River and Chesapeake Bay. Its pipe inspection system, which is linked to a global positioning system, allows DelDOT to zoom in on a particular area. “You can actually see a picture of the drainage system,” Bowman says. “The computer will also call up an inspection report, noting what repairs need to be made.”
Maintenance of stormwater structures on private property isn’t under DelDOT’s jurisdiction. “We don’t deal with them. Of course, if their system is tied into our drainage system, yes, we approved the connection, but otherwise it’s the property owner’s responsibility. The city or county doesn’t check to see that maintenance is being performed, although, since everything is considered under the same NPDES permit, we go out to investigate if there’s a complaint.
“Some building permits require that the developer either maintain the system after construction, or provide for maintenance to be done, or provide education–to members of a homeowners’ association, for example–to ensure that the system is maintained,” he continues. “Owners must maintain the stormwater ponds built for housing or commercial developments, and those ponds are under county jurisdiction.”
Mosquitoes and concerns about West Nile virus are not a big problem throughout the state. “We have received a few complaints about “˜So-and-so’s pond is breeding mosquitoes,’ but we don’t get too many complaints up here in the northern part of the state. Every so often someone might mention the threat of West Nile virus during a complaint, but we’re not too worried; the last two years the state has had lots of rain, but we’re coming off a five-year period of below-average rainfall and drought.” If mosquitoes are found, he adds, the information is forwarded to a separate state-level mosquito control division.
The North District uses street sweepers manufactured by Huntsville, AL’s Schwarze Industries Inc. The company’s heavy-duty A-series regenerative air sweepers are designed primarily for highway, airport runway, and construction sweeping; along with debris pickup, the EV-series machines provide air filtration. Schwarze’s M-series mechanical broom sweepers are designed for general street sweeping, milling, and construction cleanup. The firm’s RoadHawk is designed to handle large debris–Adopt-A-Highway bags, traffic cones, mufflers–that ordinary sweepers might not be able to handle.
Videocams and High-Velocity Water
Burns Harbor, IN’s Eagle Services Corp. provides catch basin and underground stormwater structure cleaning for area municipalities and corporations. “They employ our services because purchasing such equipment is very expensive, especially since it’s not used on an everyday basis,” explains Project Manager Bob Borns. “Plus, since we do these procedures all the time, we know all the tricks, and can get the job done quickly and efficiently.”
Eagle Services uses GapVax Inc.’s vacuum trucks, such as the HX and HV Hydro truck series, to accomplish its tasks. Described as hydro-excavators, the trucks have booms up to 25 feet, vacuum blowers rated up to 5,300 cubic feet per minute, and freshwater tanks that hold 1,400 gallons.
“We also use “˜sewer video’ to pinpoint suspected damage or blockage. Our crawling camera will find those areas, and then we’ll use a high-powered jet of water to clear them out. We have Guzzler vacuum trucks that stand alone, but we also have GapVax’s combo unit–one side has water, with a jet hose on a reel, and the other side is a vacuum unit,” Borns explains.
When the debris is removed, where does it go? “It depends upon on the site and the size and caliber of the project. Sometimes we dump onsite; other times we have dumpsters brought in so we can drain the water off and take the debris to a landfill. Sometimes the debris is treated as hazardous–if it’s possible, we remove that part for special disposal, then landfill the rest. If the debris is an unknown, we hold it aside so it can be tested by the client. It’s often good to take a sample out of a manhole beforehand and test for what’s in there before we start pumping.”
In addition to municipalities, Eagle Services also works with industrial plants and new construction. “Sometimes clients have report forms we must fill out, and, if it’s a clean-and-video job, the client gets the video.”
Borns believes maintenance is a good investment. “Our clients enjoy long-term savings and better water quality when their systems are running freely. If the sewer or stormwater system isn’t clean, water can back up into residential homes.” What’s the schedule for this type of cleaning? “Different cites are on different programs. Perhaps once a year they’ll have us inspect a certain amount of feet, and it will take some time for us to revolve through their system.”
As in other areas, Indiana residents are aware of the spread of West Nile virus. “I don’t know if it comes into play as a primary concern,” he says, “but regulations are becoming more stringent. We do clean out a lot of lagoons and ponds, to clean out silt and also to keep the pond’s capacity where it needs to be. In some cases, we’ve also high-pressure-cleaned the riprap or nonbiodegradable stone to keep the pond clean.
“We have a range of high-pressure trucks that can get rid of clogs in smaller sewerage systems,” Borns goes on. “Our pressure trucks have also been used to remove paint, and we can even produce enough pressure to cut steel! We also find that, in older piping, the videocam will reveal tree roots have infiltrated the system, and we will cut away those roots.”
Watching Out for the Fish
Tukwila, WA, takes its stormwater so seriously, it has a marine biologist on staff. “Our marine biologist has been with us 10 years. He helps us comply with regulations,” says John Howat, Tukwila’s superintendent of sewer and surface water. “Also, anything that has to do with a spill in a creek, he’s there to tell us how to repair it. He also runs our incubator program, where salmon are raised for release. He’s the liaison between us and Washington’s Fishery Department. The city has an urban environmentalist on staff too, who works with our marine biologist.”
Tukwila uses its own staff to perform maintenance services. “We do hire out some stuff, but not maintenance,” Howat says. “That’s a big issue around here–a nearby town contracted out its maintenance, which ended up costing it millions of dollars, because the contractor didn’t do it right. I have my own staff; it’s less money in the long run to do work in-house; plus you have more control. Our city breaks up the workload. There’s a water department, a sewer department, and a department of roads, which does the street sweeping. My crews do maintenance on the storm system and clean basins. We send a video camera through between 20 and 25,000 feet of storm and sewer a year, inspecting for problems.”
Howat’s staff uses Vactors to clean out catch basins. “We dewater the debris, take it to a transfer facility, and test it. If the test is OK, we take the debris to a certified dirt landfill. If during testing we discover we have a “˜hot load,’ we find a place to take it, like a specialized landfill. Also a couple of limekilns, which make concrete, can burn that debris; they mix it into asphalt or concrete. But we haven’t had a hot load in quite a while. We rarely have a problem anymore, unless there’s a spill on the road.”
Each street receives a sweeping twice a year on average. “It depends upon traffic patterns, and the season–for example, after a snowfall, we need to remove the sand that had been laid down.”
About 2,500 cubic yards of material are yearly removed from, or prevented from entering, the city’s stormwater system. “That’s between ditch cleanings, street sweeping, and catch basin cleaning,” Howat explains. “We get the entire city cleaned once every five years–although I’d like to do it every three years. Right now, we’re cleaning between 600 and a thousand catch basins in the public right of way each year.”
Although Tukwila has a resident population of about 18,000, the city swells to 50,000 people in the daytime, between local industry, retail, and Sea-Tac airport.
“If we had built our stormwater system to compensate for just the live-in population, it wouldn’t have worked.”
A public education program is also in place, to prevent pollution. “Any new projects the city sponsors contain catch basins that are labeled “˜Drains to stream–Don’t pollute.’ Through the local paper, the Hazelnut, we also send residents other reminders about polluting. We’re trying to get citizens to work with us. We tell them, “˜If you see water overflows in the winter,’–which often means the storm sewers are blocked–“˜please call us.'”
All this maintenance turns into long-term cost savings. “Along with water-quality issues, a clean system is a happy system,” Howat chuckles. “It will cost a lot more money if you don’t clean out the system and then have to repair. When we took over responsibility of a formerly unincorporated area from the county, it had not been cleaned in 30 years. What a mess! Doing maintenance on a regular basis, you’re saving money in the long run. It can be really expensive to get rid of problem dirt.”
Maintenance of stormwater structures on private property is the property owner’s responsibility. “We don’t have enough people to go around and check these structures–I wish we did. Someone will call us to complain: “˜My parking lot drain is clogged.’ I go over there, look at it, and ask, “˜Did you clean it?’ I usually get the response, “˜Oh, I’m supposed to?'”
Some building permits require developers to either maintain the stormwater system after construction, or provide for maintenance to be done. “That’s new to us; the city instigated that just recently. We don’t inspect new construction, but if there’s a problem I go out there and tell them what they have to do. I wish I had a group to inspect restaurant grease traps, too–that would help us avoid some problems. The street department used to handle stormwater, until 1989, when the city broke stormwater off into its own department. Our department is now a lot bigger, and we’re under NPDES Phase II. We’re going to have to start inspecting for runoff to local streams,” Howat explains.
As far as the concern over standing water in stormwater structures and the possibility that mosquitoes are breeding, he notes, “We haven’t inspected for that yet, but I think it’s on the horizon, because we have talked about West Nile virus. If we have birds die around here, it will raise a red flag about the disease. Just recently dead crows were found south of here, and the Fish and Game people think it might be West Nile virus–they’re still testing the birds. We might hire out the inspection and cleanup for that–mainly in the new big retention ponds. We try to clean the structures out, to make sure they don’t smell. We try to be good housekeepers, good neighbors. In the past, we’ve found beavers in our pipes; the wildlife people had to come to trap them.” Remembering the beaver infestation causes Howat to chuckle. “I’ve been working here 25 years. I grew up here. My crew and I like doing our jobs–it’s fun. I’m going to do it until I retire. I love it.”