May 2007

The Power of Pumps

Communities rely on permanent pumping stations and portable pumps for flood control.

Fred Remen knows pumps. He has to. He works with the South Florida Water Management District (SFWMD), an agency responsible for maintaining more than 2,500 miles of canals in 16 rapidly growing counties in the Sunshine State, stretching from the diverse ecosystems of the wild Everglades to the touristy Florida Keys.

The district is responsible for 300 major water control structures and several thousand minor ones. Many of the major ones are large, multipiece pumping systems designed to move stormwater and floodwater out of low-lying residential areas. Gravity can’t do the job without these pumps.

“Pumps are definitely a way of life here in south Florida,” says Remen, director of field operations with the SFWMD.

Photo: Global Pump

Multiple-piece pumping-systems are built to direct stormwaater out of low-lying areas.

And Remen is far from alone. As developers continue their push to build on undeveloped land, even if that land sits in areas prone to flooding, municipal agencies are turning more frequently to manmade pumping systems to do the job that gravity alone can’t.

Many of the systems are similar to the ones Remen and his agency rely on: large, permanently installed pumping systems operating in low-lying areas prone to seasonal flooding; busy urban locales where engineers can no longer build adequate drainage systems; or riverfront areas that need additional protection.

Other systems are temporary. Municipalities might need portable pumping systems for routine cleaning or maintenance of their storm sewer systems, catch basins, or ponds. Others might call on them for the emergency cleaning of a storm sewer after particularly heavy rainfall.

Pumping systems have played a major role in the cleanup efforts in hurricane-battered communities along the Gulf Coast. Their high-profile work in New Orleans and neighboring communities following Hurricane Katrina garnered headlines, but pumping systems have offered municipalities hope for dealing with flooding and stormwater problems for decades.

“We do offer solutions for a lot of communities,” says Dave Sheldon of Roseburg, OR–based Romtec Utilities, a maker of pumping systems and stormwater lift stations. “A good share of our business comes from new development where they are hooking sanitary sewers to a gravity sewer. The gravity may no longer be causing the wastewater to flow, so they need a pressure line and submersible pumps to then dump that back into the treatment plant.

“Stormwater is another big part of our business,” adds Sheldon. “This is especially the case with new developments. Instead of allowing the runoff from city streets, large industrial complexes, airports, or large parking areas to run straight into streams, municipalities want to control it, put it in some type of detention pond. Sometimes that means using pumping systems to stop it from where it would overflow and then pumping it into streams or other areas.”

The makers of pumping systems expect demand for their products to increase as housing and commercial construction continues its heady pace. And there are, unfortunately, always heavy rains and natural disasters that leave waterlogged communities in their wakes. Municipal officials will continue calling on pumping systems in these cities and towns, too.

Here are some ways in which municipalities across the country have used pumping systems to solve their stormwater and flooding problems. Each case study provides its own lessons in selecting the right pumping system for the right job.

Installing a Submersible Pump for Flood Control

Photo: ITT Flygt

Photo: ITT Flygt

Photo: ITT Flygt

Photo: ITT Flygt

Photo: ITT Flygt

Keeping Up With the Building Boom
Remen doesn’t see any end to the SFWMD’s reliance on pumping stations. After all, developers keep building housing subdivisions and are showing little inclination to stop.

The challenge comes because counties are permitting residential developments in low-lying portions of southern Florida. These areas are especially prone to flooding, and southern Florida never lacks for heavy rain. It’s up to Remen and his agency’s engineers to redirect the storm flows from these frequent storms away from residential areas.

It’s a challenge the management district would never be able to meet without pumping systems. “We have no choice, really, but to go with pumps in many areas,” Remen says. “We like to go with gravity flow, of course, but in many areas that we are serving, the residential areas may be lower than the canal systems that are being used to serve them.”

The agency today manages more than 50 pumping stations, ranging from 200 horsepower to several thousand. In all, Remen’s agency is responsible for more than 100,000 horsepower worth of pumps.

Pumps today are more important here than ever, Remen says, mainly because the pace of development has increased so rapidly during the last 10 years.

Today, officials with the agency are in the midst of a huge renovation of the Central and Southern Florida Project, a massive flood control plan dating back decades.

Built by the Army Corps of Engineers starting in 1948, the project includes 21 water control spillways, 75 secondary drainage structures, 250 miles of flood control channels, and the 144-mile Herbert Hoover Dike. The corps constructed the project, which serves an 18,000-square-mile area that extends from south of Orlando to Florida Bay, to help control the flooding that was common in the area and as a means of providing a clean water supply to nearby agricultural and urban areas.

The project has performed both tasks well for decades. But it has had unintended consequences. The most serious? The stormwater it pumps into the Everglades is at times polluted, filled with soils, phosphorous, weeds, and other debris. The renovation project is adding enhancements—the most significant of which are several large pumping stations—that, instead of pumping stormwater directly into the Everglades, will send it first through large stormwater treatment areas that remove chemicals and pollutants before the water hits the environmentally sensitive Everglades.

The project is an important one, but also a huge task. Engineers built a prototype stormwater treatment area 15 years ago to prove that such zones could effectively clean polluted water. Such areas are large marshes that naturally remove phosphorous from the water. The district relies on pumping systems to move stormwater through these marshes. That initial treatment area did its job well, reducing the pollutants severely. Once these positive results came in, the management district embarked on its aggressive construction program. This involved buying and swapping land, always a time-consuming and expensive process.

“Because Florida is so flat—and that’s the whole reason our agency exists—we have to move the water to these treatment areas. We can’t rely on gravity to do it for us,” Remen says. “If not for the pumps, we wouldn’t be able to move the water.”

How complicated is the series of pumping systems—the key part of the stormwater treatment areas operated by the water management district—now operating in southern Florida? Just consider one stormwater treatment area recently designed by the district’s engineers.

Known as STA 1 West, the treatment area consists of almost 7,000 acres, more than 10 square miles, of agricultural fields that have been converted to wetland treatment systems designed to reduce phosphorous loads entering the Everglades. Located in the western portion of Palm Beach County, construction of STA 1 West in 2000 involved the creation of about 6,670 acres of treatment wetlands, 14 miles of levees, three concrete spillways, culverts, and, of course, pump station G-310.

This important pumping system consists of six individual pumping units, two electric pumps that can move 100 cubic feet of water every second, two diesel pumps with the capability of moving 470 cubic feet of water a second, and two more larger diesel pumps that can pump 950 cubic feet of water every second. With a capacity of 3,040 cubic feet per second, the pumping system discharges almost 2 billion gallons of treated water every day.

Photo: Global Pump

Instead of allowing potentially polluted runoff to head straight for streams, municipalities use pumping systems to redirect the overflow.

That’s impressive. But so is the fact that the management district also operates an exact duplicate of the G-310 pump station about 2 miles away. The duplicate, known as the G-335 station, is an intake station, located at the point where the water pushed through by G-310 is discharged.

Both G-310 and G-335 are what are known as formed suction inlet pumps. Each uses propellers that create a vacuum inside a large intake pipe that pulls in water from the lower canal side of the pumping station. Water moves through the pipe and is discharged into the storage area on the other side. A screen at the front of the intake prevents weeds and debris from entering the system.

“We’re doing what we can to protect the Everglades and to keep stormwater moving throughout our district without impacting all these low-lying residential areas,” Remen says. “We wouldn’t be able to do it without our pumps.”

A Flexible Solution
Southern Florida isn’t the only community that has benefited from pumping systems. Communities turn to them frequently because they are flexible enough to solve flooding and stormwater problems of all sizes and intensities.

The City of Santa Barbara, CA, for instance, last July used pumps to improve the municipality’s summer water quality. The goal behind the program? Pumping systems would divert polluted runoff from storm drains quickly into sanitary sewers. The water could then be funneled into the city’s treatment areas, where the pollution and bacteria would be stripped away.

The city turned to pumping systems for the same reasons so many other municipalities have. Santa Barbara is a popular summer destination, with its population increasing during the warmer months. These months are also when people are more apt to heavily water their lawns, wash their cars in the streets, and hose off sidewalks and parking lots. The problem is that this urban runoff, especially during dry periods, often contains bacterial pollutants from everything from soil to animal waste. Oil mixes in with water that residents spray in parking lots and into city streets. Even pieces of garbage are picked up by the water flow. And eventually, all that muck can flow into the creeks and streams that lead to the Pacific Ocean.

“We’d been concerned with the dry-weather urban runoff we’d been getting,” says Jill Zachary, creek restoration and water-quality manager with the city. “It was especially bad at certain areas. We needed to address all the pollutants and bacteria that the runoff was picking up.”

This problem was especially acute at Haley Street in a residential area near downtown Santa Barbara. The Haley Street storm drain, serving a busy tourist area of antique shops and bed-and-breakfast inns, shoots runoff into nearby Mission Creek. The creek then flows into the ocean at the popular East Beach. City officials, then, couldn’t allow bacteria and pollution to get swept up in this busy storm drain.

Santa Barbara officials tackled this problem with their Haley Street Low Flow Diversion Project, which uses a lift station with submersible pumps to reroute polluted runoff from the Haley Street storm drain to the city’s sanitary sewer system, where it can then be treated. The goal is to both improve water quality and cut down on beach closures.

City officials initiated the project after a Mission Creek Watershed study revealed high levels of bacteria. Mission Creek is an important waterway, one of Santa Barbara’s three major creeks, all of which flow to the ocean. The watersheds surrounding all the creeks are definitely urban areas, with residential, commercial, and small patches of industrial development. Roads, parks, and open space also surround the creeks. The potential for pollution is great.

“Over a number of years, our water-quality monitoring had found high levels of bacteria coming out of the storm drain during dry weather,” Zachary says. “The work we did at Haley Street is part of our larger bacterial reduction program. It was a good location to divert dry-weather runoff from our storm drain to the sanitary system.”

Haley Street runs alongside Mission Creek, and its storm drain is located just 20 to 30 feet from its outflow into the creek. Here, the storm drain line sits lower than does the sewer line. To divert the water to the sanitary sewer, city officials had to pump the water up a distance of 5 to 6 feet. To do this, engineers from Oakland, CA–based URS Corp. ordered a pre-engineered lift station from Romtec Utilities.

The lift station, which Romtec delivered to Haley Street on two large trucks, includes a precast concrete wet well that measures 6 feet in diameter and is more than 13 feet deep; two Flygt N series pumps; a preassembled valve vault; and a UL-listed control panel and pump disconnect panel. Construction crews closed Haley Street for most of a day while they installed the lift station.

The system is not complicated to operate, a plus for city officials. In dry weather, the inlet valve is turned on to trap the flow and pump it to the sanitary sewer line. In wet weather, the valve is turned off.

The lift station runs from April 1 to October 1, the dry-weather season in Santa Barbara. During an average day, the station’s electronic control system records that the pump starts 20 to 40 times, with a total run time for both pumps of 30 minutes to an hour. City officials estimate that the station pumps from 9,000 to 18,000 gallons of water every day.

The Haley Street project is just one facet of a larger dry-weather diversion project that the city is currently running. So far, it’s been working as city officials had hoped.

“So far, we’ve had no problems,” Zachary says. “We’re happy with the way it has worked.”

Easy to Use
Engineers turn to pumps for less dramatic projects, too. Consider Rumsey Rancheria, a community of 30 new homes in Brooks, CA. Engineers with the civil engineering firm of Laugenour & Meikle in 2005 ordered a lift station from Romtec to empty a stormwater detention pond that serves the subdivision.

Again, the system is not complicated. Water drains to the subdivision’s detention pond. The lift station and its pumps then move the water to a nearby creek, something that couldn’t have been accomplished if engineers had relied on gravity alone.

Todd Tommeraason, an engineer with Laugenour & Meikle, says the system’s ease of use is one of its best selling points. “The people from Romtec basically came out and put it all together for us,” Tommeraason says. “They hook it up and hand it to you as a running unit. The contractor didn’t have experience in that area. It was a lot easier for him to dig the hole, get it set up, and have Romtec come out and hook it all up.”

Battling Katrina’s Aftermath
Pumping systems have more than played their part in the ongoing cleanup efforts in New Orleans and other Gulf Coast communities hit by Hurricane Katrina.

Photo: Global Pump

Whether for emergency cleanup or permanent protection, pumps can take on the job.

For instance, officials in St. Bernard Parish, located just 5 miles from downtown New Orleans, are relying on 22 pumps manufactured by Deerfield Beach, FL–based Moving Water Industries. The Federal Emergency Management Agency (FEMA) last December ordered 22 of the company’s PrimeRite and Hydraflo pumps. The pumps will help move polluted water out of the area.

“This allows people to move back into their own areas,” says Marc Boudet, vice president with Moving Water Industries. “They needed to get the sewage out of that area, and St. Bernard Parish was about 90% uninhabitable when FEMA contacted us. It’s a good feeling to be able to help.”

The pumps are mobile. After officials are finished pumping sewage out of St. Bernard Parish, they can move the pumps to other areas.

Sinkholes, Too
Sometimes, municipalities call for pumps for extremely rare occurrences.

This happened in 2004 in the city of Sterling Heights, MI. In August of that year, a sewer line burst under 15 Mile Road, causing a 30-foot-deep sinkhole that stretched 60 feet wide and 160 feet long.

Photo: Global Pump

Temporary pump installation in Albuquerque

Authorities quickly shut down the road. They also had to evacuate several families living in the nearby Villa Fontana subdivision.

To solve the problem, crews injected the ground with concrete. First, though, they had to call on pumping systems from Davison, MI–based Global Pump to reroute an estimated 60 million gallons of sewage.

“An enormous chunk of Michigan had fallen into the hole,” says Terry Lindermere, vice president of engineering with Global Pump. “We were onsite supplying pumps to pump out manholes on an emergency basis.”

Crews had to lay several thousand feet of bypass piping during reconstruction work. Global Pump’s pumping systems did the heavy duty of rerouting the sewer water for the duration of the work, which lasted until March 2005.

This is far from the only recent pumping projects Global has taken on. In August 2006, Global sent pumps to Flint, MI, for a bridge-replacement project. The Michigan Department of Transportation used eight 250-horsepower diesel-driven Trash Auto Prime pumps from Global while crews replaced the city’s Chevrolet Avenue bridge. The pumps allowed water to bypass the 66-inch sewer running through the bridge’s foundation. To guard against possible heavy storms, seven of the Global pumps were operating as duty pumps on level control while the eighth was installed for standby purposes.

In September, the City of Albuquerque, NM, used four diesel-driven Trash Auto Prime pumps on a sanitary sewer bypass of up to 6,000 gallons per minute. The city needed to continuously bypass an existing sewer running through residential and commercial areas. Because of road crossings, four road ramps were specially designed to allow sewage to flow through them while vehicles drove over them. This allowed traffic to continue crossing the bypass.

Lindermere says he expects municipalities to keep calling Global for this kind of project. “Municipalities are always going to need pumps, for whatever reason,” he says. “When a municipality, for whatever reason, has its regular pump station down, either on a planned or an emergency basis, we’ll be supplying pumping equipment to be able to bypass that plant for the duration of the work. They call on us when they need us.”