The sound of a street sweeper entering your neighborhood is scary enough to turn any Long Beach resident into a track star, as they race out the door to avoid a citation for being parked on the wrong side of the street.
But perhaps more alarming is that potable water is being used by these machines to clean streets, while residents across the state face conservation mandates.
Although the Long Beach Water Department (LBWD) operates a fairly substantial recycled water network, an official from the department stated that street sweepers use potable water to carry out their work. Public Works, which oversees the city’s street sweeping program, lists the Elgin Pelican broom sweeper and the Johnston 7000 vacuum sweeper as the vehicles that make up its fleet.
At Tuesday’s city council meeting, the council voted to approve the purchase of four new Schwarze A7000’s at a cost of around $1.2 million. The Schwarze models will continue to use water to suppress dust while they clean city streets.
Jim Cool, an engineer in the Environmental Services Bureau with the city’s Public Works Department, said the sweepers clean about 156,000 miles of roadways annually in the city. However, to clean the roads safely and to remain in compliance with the South Coast Air Quality Management District (SCAQMD), Cool said the sweeper must meet certain standards. The city must operate street sweepers that work on clean fuel, natural gas, or an equivalent.
They must also meet certain parts per million counts established by the state’s air resources board, stipulating that sweepers reduce the introduction of harmful particulates into the atmosphere, which have been linked to respiratory disease, certain cancers and even premature death.
Cool said for those reasons, Long Beach is bound to purchasing certain types of models with sweepers using water as a dust suppression method.
“Air Quality Management District mandate that our sweepers are PM-10 compliant, which means they’ll pick up real fine particles of dust,” he said. “So, to be PM-10 compliant, which is parts per million compliant, we have to use water to capture that dust.”
The 20 Pelican sweepers and two vacuum sweepers that the city currently employs have a water capacity of over 200 gallons. They are filled about two times per day, according to Cool. The Schwarze models approved by the council last night contain a 250 gallon water holding tank.
Based on those numbers, if each of the city’s 22 machines operated daily on its Tuesday through Friday sweeping schedule, the street sweepers could consume over 1.2 million gallons of potable water each year.
That number is roughly the equivalent of 10,900 residents' daily use of water, according to recent usage statistics.
The statistics showed the per capita water consumption to be about 110 gallons per person per day. A small figure, but with daily fines of up to $10,000 per day facing water suppliers who don’t meet Governor Jerry Brown’s mandate to conserve water, every drop could seemingly count.
Sam Atwood a media relations manager with the SCAQMD said that the district does require the use of clean air sweepers but he didn't recall a requirement for cities to use water to suppress dust.
"That's the first I've heard of that," Atwood said. "Of course my city uses street sweepers and I've never seen one that uses water."
As of April 22 2015, a waterless version of the Pelican was listed as an approved sweeper by the SCAQMD. The department tested several models before deciding to go with the Schwarze model, stating that it "offered the best operation fit and cost effectiveness."
At over $300,000 per vehicle, it's probably unrealistic to expect a city to perform an overhaul on its street sweeper fleet overnight, but given the state’s current drought and the executive order from the governor, it’s unclear why an approved waterless sweeper wasn’t explored by the city. Cool was not immediately available for comment.
Cool said that the city has a way of telling how often drivers are using recycled water, adding that approximately one-third of the water the sweepers use is recycled. He acknowledged the department could be doing a better job of using recycled water when available to sweepers.
In fact, that will be a focus of a meeting with the superintendent of street sweeping, whom he said he plans to meet with in the near future. Cool said the fact that the system doesn't reach the entire city does present logistical issues. For example, sweepers servicing the downtown area would have to drive to Cherry Park in order to fill their tanks with recycled water.
A map of the LBWD's recycled water system, courtesy of the LBWD website.
In 2013, the LBWD expanded its recycled water system that now reaches from the east side to the west side of the city. Further expansion could make the city's street sweepers' work more sustainable, in spite of the amount of water they currently use.
Once the system is complete, it is projected to increase citywide consumption by approximately 9,000 acre feet annually or 15 percent of the city’s water use. One acre foot of water is approximately 326,000 gallons of water, which means at the per capita usage for the city (110 gallons per person per day) the savings could equal the daily water use of nearly 27,000,000 people.
The recycled water used by the city is categorized as “disinfected tertiary” recycled water, meaning it’s been treated for contaminants such as nitrate and phosphate, and is filtered and disinfected. It is the highest level of treatment. Water deemed as disinfected tertiary is approved for a multitude of uses, including residential landscaping, parks and playgrounds, golf courses and freeway landscaping.
The system map on the water department’s website shows a system that spans from El Dorado Park in the East to Virginia Country Club in West and descends down to Bluff Park in the south. However, it does have sizable gaps in the Downtown and North Long beach communities, making it cumbersome for street sweepers to utilize its outlets to fill trucks.
Kaylee Weatherly, an assistant to the department’s general manager said that once the recycled water project is completed, expected to happen in the next few weeks, it should surpass projections. However, the gaps will remain in the city, as it mostly coincides with large park spaces spread throughout the city.
“We’re not a big user of water, for them to put in hydrants for us, it has to make economic sense for them,” Cool said of the water department. “If they can run it to a park or to a golf course where there’s a lot of recycled water usage, that’s where it makes sense for them.”