Landscape Architect Articles

From Trash to Treasure02-01-03 | News

From Trash to Treasure

The Building of the HB Sports Complex

By Sean Stowell

Decades of trash, landscape cuttings and other non-hazardous materials are slowly evolving into a revenue generating sports complex in the coastal city of Huntington Beach, Calif.

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Because part of the site was a landfill, a process called Deep Dynamic Compaction (DDC) was used to compact the trash. Grading on a project like this would normally take a month, but because of the special considerations of this particular site, it took nearly four months. PHOTOs by Brian Barsuglia

Prior to 1927, mining took place on the northeastern part of the site. From the 1930s to the 1950s, the site was used to dispose of drilling muds very common in the Huntington Beach area. From the 1950s to the 1980s, mushrooms were farmed on the southern section, while the entire northern section, near the Public Library had been a landfill for many decades.

LCN was given an exclusive tour of the project, which by the time you read this will be at or near completion.

While there is a lot that has gone on and a lot still going on, one of the major undertakings of the project was the enormous amount of grading that took place on the site.

The grading, provided by Nelson & Belding, was done with six 651 Caterpillar scrapers; two 824 Caterpillar dozers for finishing and tamping and a Cat 450. Several environmental groups have visited the site in the little more than a year that the project has been going on. A softball umpires association even made a visit to the site to take a look at the eight softball feilds that are being built. At the time this article was written, grading on the ball fields, fine grading and some slope building still needed to be done.

According to Brian Chesnut, Project Manager for ValleyCrest, approximately one million yards of earth was moved at the outset of the project. Because part of the site is an old landfill, special precautions had to be taken with the trash that was sitting under the dirt.

What needed to happen was all the trash had to settle as much as possible. No easy task according to Chesnut.

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A process called Deep Dynamic Compaction (DDC) was used to compact the trash and an Alternative Final Cap (AFC) was put on top of the landfill area to prevent water from penetrating the trash below, thus contaminating the water table.

The DDC was done with a 250-ton crane dropping a 32-ton weight into the ground from 50-100-feet in the air. When the weight hits the ground it creates a hole, compacting whatever is beneath and it sends soundwaves out approximately 25-30 feet, compacting that area as well.

This sent a loud booming sound over the city upsetting some residents who thought loud cannons we being shot in their own backyards. Workers from ValleyCrest had to then inform their neighbors when the DDC would be happening to avoid any onsets of panic attacks.

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The grading of one million yards of dirt usually takes about a month, according to Chesnut, but because of the AFC, DDC and other regulations from various boards and commissions, it took nearly four months to get the grading done on this project.

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Another concern arising from the former landfill was the affect the decades-old trash below the grade would have on the project. Concerns were posed about the trash and the methane gasses that they could emit. Chesnut said that ValleyCrest hired a medical doctor to design a health plan, covering anything and everything that could happen on the site.

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During the project the AQMD, CAWB, LEA, and just about every ?EUR??,,????'?????<

Grading was done by Nelson & Belding of Gardena, Calif., and they brought out the big equipment for this project. According to Carter, Nelson & Belding used six 651 Caterpillar scrapers; two 824 Caterpillar dozers for pushing, finishing and tamping; and a Cat 450 with slope boards.

Originally it was estimated that 30,000 yards of dirt was to be exported from the entire site. Instead, 80,000 yards was imported to the site. Only onsite dirt could be used for the Alternative Final Cap (AFC) on the area that used to be a landfill due to California Water Board requirement. Dirt from the former mushroom field had to be used, leaving it rather sparce. The imported dirt was used to fill the former mushroom field.

The California Water Board (CAWB) of course was concerned about stormwater pollution. ValleyCrest had to hire an independent consultant, who put together a customized plan, that fits into a binder that looks to be about 4 inches thick. The crew had to make weekly reports on any possible stormwater pollution every day for a year.

On the day that LCN visited the Sports Complex, a mild storm had just passed through Southern California and some fine grading needed to be done to repair tire marks that were made in the mud.

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One unforeseen challenge came in the form of importing dirt. Originally it was thought that 30,000 yards of dirt would be exported, instead, 80,000 yards was imported to the site. The reason for that was only onsite dirt could be used for the AFC layer, per California Water Board requirement. In order to complete the grading, dirt was taken from the farm area and moved to the landfill area, leaving one area in workable condition while the other was low on the needed materials.

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California is bracing for a mild El Nino system that will send some much needed rain to the parched Southland. While the rain is good, it wreaks havoc on construction sites. The ValleyCrest crew had to take a gamble and put in the hardscaping, do the major grading, and put in plantings hopefully before El Nino hit. As of the time this article was written, El Nino has been nowhere to be found, making the work at the Huntington Beach Sports Complex on time and under budget. Which makes any client happy.