Balancing Act

Faced with unforgiving terrain and wildly fluctuating demand for service, Lake Arrowhead CSD works hard to keep its system on an even keel.
Balancing Act
LACSD Mechanical Supervisor Tim McIntire remotely checks the status of the district’s 21 wastewater pumping stations before heading into the field. (Photography by Collin Chappelle)

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California’s Lake Arrowhead Community Services District is located in the San Bernardino Mountains, 90 miles east of Los Angeles. The resort area is the picture of tranquility on the surface, but its water and wastewater infrastructure requires a constant effort to maintain balance, the biggest challenge facing the system.

The topography of the area made it a perfect site for the construction of a dam and the creation of Lake Arrowhead, which sits optimally at 5,270 feet above sea level and provides the district with water. That same topography, however, has presented a challenge for the district’s sewer system, which operates 20 lift stations to cover a topography ranging from 4,000 to 6,000 feet above sea level in an area covering only 58 square miles. About 40 percent of the district’s service area slopes at greater than 30 percent grade.

The ebb and flow of tourists and seasonal residents also results in wide fluctuations in demand on the system.

Tim McIntire has lived in the area for 50 years and worked for the district for more than 28. He’s the mechanical maintenance supervisor, with responsibility for the equipment at the system’s two water treatment and  two wastewater treatment plants, lift stations and pumping stations. Assisting him is Doug Blackburn, responsible for electrical instrumentation maintenance and Alan Clanin, equipment mechanic.

“Those are our primary duties,” says McIntire. “But there are only three of us, so when it comes time to pull a pump, we all pitch in.”

Water drawn from artificial lake

The area has a colorful history, but the district is a fairly recent creation. It was formed in 1978 to purchase a privately owned water system serving the community of Arrowhead Woods, which surrounds Lake Arrowhead and also Deer Lodge Park. Water is drawn primarily from Lake Arrowhead through a system that includes 18 water storage reservoirs, nine pressure tanks and 22 water pumping stations. The pipes and components in the water distribution system are in good shape, says McIntire, with very few leaks or breakages reported. “It’s just the occasional pump issue, mostly on the electrical side,” he says.

The district assumed control of wastewater services from San Bernardino County in 1983. This service area is slightly larger than its water coverage, including the communities of Twin Peaks, Rimforest, Skyforest, Crest Park, Blue Jay, Cedar Glen and Agua Fria.

System sewer pipes are made of a variety of materials ranging from asbestos concrete to concrete, steel and PVC. The pipes range in diameter from four to 42 inches.

“The sewer lines aren’t in quite as good overall shape as the water pipes,” says McIntire. “We have some inflow and infiltration [I&I] issues in the oldest sections.”

The water system works hardest during the summer when the population swells from as few as 12,000 to as many as 30,000 people during summer weekends.

Seasonal population challenges operators

“Our water side operates at its peak in summer while our wastewater system is just cruising along,” says McIntire. “In winter, we don’t provide irrigation to residents and with less than half the population living here, the demand plummets and we get low water flow. However, with 97 percent of precipitation falling between November and April, we’re hit hard with I&I from heavy rains and snowmelt. Going back and forth, it can drive us crazy.”

In 2003, the district embarked on an ambitious program to decrease its draw on the lake by half. Those initiatives include: improvements in water treatment plant efficiency, water conservation, development of groundwater resources and the use of supplemental water from the San Bernardino Valley Municipal Water District under the State Water Project.

In 2006, the State Water Resources Control Board issued an order that limited the district’s water rights to withdrawals up to 1,566 acre-feet per calendar year, commencing in 2008. Those limits would be further reduced any time the lake’s surface fell below 5,100 feet above sea level.

“We’re engaged in an aggressive water conservation effort, looking at every kind of usage,” says McIntire. “One big problem was that people were really overusing irrigation, watering their properties even when they weren’t living here.”

Irrigation is now only permitted on Monday, Wednesday and Friday during evenings and nights and prohibited from mid-October through April. Residents who overuse water are subjected to an efficiency audit and limitations have been put in place regarding landscape design. Treated wastewater is also used as graywater for local irrigation at the resort’s country club.

Balancing conservation and revenue

However, while the efforts have succeeded in reducing water usage, the district faced an equal shortfall in water revenue.

“Water rates had to rise significantly to cover our fixed costs,” says McIntire. “It’s the catch-22 of water conservation, but we’re finally reaching the point where water rates and costs are starting to come into balance.”

Reduction in water use has also reduced some of the strains on the wastewater system. However, the district uses other tools in its tool kit, first corralling I&I in traditional fashion by inspecting, maintaining, repairing and replacing sewer pipes. The district owns and operates a SuperVision closed circuit crawler camera by Envirosight, and a Vactor jetter and rodding machine.

Work on sewer pipes has included anything from relining to repair and replacement.

While the district once operated its own construction unit, contracting out larger construction jobs is more cost-effective, allowing maintenance crews to devote more attention to smaller repairs and routine care.

“By applying these programs, we’ve brought the I&I down substantially,” says McIntire.  “At the same time we’ve upsized our wastewater treatment plant to handle more inflow from winter precipitation. We still see some big numbers that go beyond our limit to treat, but we’re continuing to work to bring those numbers down.”

Lift stations provide push

While the sewer system relies as much as possible on gravity, it’s the 20 lift stations that provide the extra push to move sewage to the system’s two wastewater treatment plants.

“The lift stations are designed to provide enough lift to let gravity take over for as long a distance as possible,” says McIntire.  “The largest lift station, Grass Valley, manages an elevation of 200 feet, while the smaller stations range from 30 to 60 feet.”

Many of the larger lift stations operate under capacity, allowing for population growth in the communities served. Grass Valley possesses a capacity to run at 4,500 gpm, but most often runs 24 hours a day at 600 gpm. The second biggest station, with a capacity of 1,500 gpm, runs at 450 gpm for about five hours per day.

The smaller lift stations operate on air injection, emptying tanks of 100 gallons every time an electronic valve indicates the tank is full.

Daily personal inspections

The system’s supervisory control and data acquisition (SCADA) system provides electronic monitoring, but the lift stations are personally inspected each day.

“It may be a short distance across the lake, but it’s a 5- or 6-mile drive around the perimeter, so it’s time consuming,” says McIntire. “You can bet that when we get a report on a problem, the lift station in question is located on the wrong side of the lake.”

The biggest threat to the main lift stations is “ragging” — when hotel guests flush wet wipes that get stuck inside the pumps.

“With the hotel in full operation, it’s a little city,” says McIntire. “The only solution is to pull the pumps and remove the fabric manually.”

The smaller air-injection lift stations require less maintenance, with staff attention limited largely to changing oil in compressors and cleaning electrodes on the level sensors.

The system also includes a series of individual homeowner lift stations in the tiny community of Rimforest.

“About 15 years ago we had a landslide that took out several houses and a section of our sewer system,” recalls McIntire. “We lost gravity flow and had to decide whether to build a bridge and replace the line. Instead, we installed 10 personal lift stations — submersible pumps with 25 gpm capability. Even if another slide takes out more of the homes on the edge, the lift stations for the remaining homes will still be functional.”

As the district continues to reduce its reliance on Lake Arrowhead, and moves to greater reliance on groundwater and outside water sources, the system will necessarily become more complex. McIntire is in the process of hiring two additional maintenance staff members to handle that transition.

“We’ll rely less and less on the lake for water,” says McIntire. “But we’ll find better ways to maintain the water and wastewater system. It’s all about balance.”



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