Was it avoidable? Or was it inevitable that a series of storms would wreak havoc on the Waimanalo Gulch Sanitary Landfill’s storm water drainage system, break open a waste cell, and wash medical and municipal waste and contaminated runoff into the sea?
At a state Land Use Commission hearing held last month on the January flooding at O`ahu’s only municipal solid waste landfill, Joseph Whelan, general manager for landfill operator Waste Management Hawai`i, Inc., claimed it was inevitable.
Whelan has argued that the rains of January 12 and 13 were equivalent to a 100-year storm and overwhelmed the landfill’s drainage system, designed to handle only a 25-year storm. Had the rains come just two months later, when construction of a larger drainage channel intended to accommodate a larger storm was anticipated to be completed, storm water would have never come in contact with waste, he and representatives from the City and County of Honolulu have said.
At the February 2 hearing, LUC members tried to determine what could have been done to prevent the spill, starting from the time the design for that new system was completed up to the weeks preceding the spill.
By the end of the meeting, it was clear the commissioners did not like what they heard, which, based on a review of state Department of Health records, wasn’t even close to the entire truth.
A Chronology
Whelan began his presentation to the commission by describing the new and improved drainage system Waste Management had been hard at work on when the rains came. A 14-to-16-foot-high berm would divert runoff from the upper part of the gulch to a culvert, which would be connected to a 7-foot-wide fiberglass pipe that empties into an existing concrete channel. The channel leads to a reservoir at the bottom of the landfill, which in turn drains to the sea near Ko Olina resort. Construction began in November 2009.
“This is an approximately $15 million project, not something that lends itself to being done in a short time,” Whelan explained.
But over the time span of less than a month last winter, the landfill was beset by three storms, the first occurring on December 19. Whelan said that according to a rain gauge at nearby Lualualei, about 7.9 inches of rain hit the landfill in some 13 hours. Storm water flowed into a new waste cell known as E6. Because water had ponded in the cell, Waste Management created a berm to prevent it from breaching and brought in additional pumps to get rid of the water.
On December 27, another major storm hit, dumping four inches of rain in four hours, Whelan said. The cell filled again with water, and again crews scurried to reinforce everything they had built after the first storm.
The last storm came in the evening of January 12 and continued the next day. Whelan said the site received 10.7 inches of rain in a 24-hour period, 6.5 inches of it in about six hours. The discharges from the landfill’s waste cell probably occurred in the middle of the night, but his company only realized some time in the afternoon that waste was leaving the landfill, Whelan said, even though his workers were on site as early as 5 a.m. that morning.
Whelan told the commission that once his company realized the magnitude of what had happened, it held a teleconference with city and DOH officials and began sampling runoff and posting warning signs at the drainage outlet, and later along the beach fronting the Ko Olina resort.
A Grilling
In September 2009, the LUC, in a 5-3 vote, barely approved an extension of Waimanalo Gulch’s special use permit, which allowed the landfill to expand by more than 90 acres. The surrounding community, which opposed the extension, had had enough of a landfill that was supposed to have closed years ago. But, in the end, there just didn’t seem to be any other option.
“The very fears that the community raised before this commission were realized by this spill and then it comes back to us … because we passed it,” LUC chair Vladimir Devens told Whelan.
When it came time for commissioners to question Whelan, Devens was aggressive from the start. He wanted to know what warning, if any, was given to the community and to residents of Ko Olina to alert them that syringes and blood components might be floating in the ocean.
Whelan responded only by saying that a collective decision was made to post warning signs at the storm water outfall.
“We assembled those signs at the city, and put those up at 4 or 5 in the afternoon. We didn’t realize medical waste was an issue until about that time. Once we realized there was, we had already put up warning signs,” he said.
Commissioner Normand Lezy, one of the commissioners who opposed the extension, asked Whelan what evaluation, if any, Waste Management did after the December 27 storm to assess the possibility that the reinforcements could fail and allow waste to leave the cell.
“It sounds like, in each instance, you were kind of dodging a bullet. The first time it flooded, fortunately there was no discharge. The second time it flooded, there had been some sort of work done to build a berm and strengthen the cell to avoid a discharge. You then get to the third event, more rain, more water, and there is an actual discharge. So what I’m wondering is, what sort of evaluation was done to quantify what the risk was that there would be a discharge if more rain and more water ended up in the cell?” Lezy asked.
Whelan said that his company had no advance notice that such a huge storm was coming and that the landfill is only required to handle a 25-year, 24-hour storm. (According to the company’s surface water management plan, however, the landfill should be able to handle 9.1 inches of rain within 24 hours, which appears to be more than what fell during the first two storms.)
He added that after the storm water drain pipe clogged with silt during the first storm, his company evaluated why that had happened and built a berm up above it to try to stop debris from clogging it again. It also used boulders to divert and slow runoff and built a small dam behind the berm.
“All of that failed because of the magnitude of that storm,” he said.
Lezy asked, “Do I understand you to say that, at least in your company’s estimation, that this event was unavoidable?”
“Yes,” Whelan said.
Lezy asked whether, as part of the planning for the new diversion system, any particular cells were identified as being at risk for flooding.
Whelan said that the DOH solid waste permit acknowledged that during construction of the diversion system, there could be a time when storm water could overflow into the cell.
Lezy then asked whether there was any reason why cell E6, which had only been in operation for a couple of months, didn’t simply stop accepting waste while the long-term diversion project was being finished.
Whelan responded that E6 was the only area that had any capacity left.
To Devens, it was clear what had happened.
“What it sounds like to me is that you folks went ahead with this construction, you did not take any proper preventative measures, and just hoped it wasn’t going to rain. And when it did, you folks were caught with your pants down. This is what happened. Isn’t that really what happened in this case?” he told Whelan.
Devens continued, “[W]e have this massive discharge and there was just a lack of urgency in my mind with the public not knowing the extent of the discharge and what was actually contained in that discharge. I was shocked when I heard that there were needles on the beach at Ko Olina, in Nanakuli, down to Wai`anae. I was also shocked to see that people were picking that up with their bare hands and in slippers. And yet there were no warnings out there to the community warning them of those dangers.”
When Whelan pointed out that the improved drainage system was proposed more than ten years ago, but could only recently be constructed, Devens responded, “Over the last ten years, couldn’t you have figured out what the preventative measures were going to be while the construction was going on instead of leaving everything open like it was? … I don’t buy that this was unavoidable. I hear what you’re saying but it doesn’t make any sense to me.”
Hindsight
A review of records from the state Department of Health’s Solid Waste Branch suggests that with regard to designing an effective drainage system, the city and Waste Management had backed themselves into a corner, quite literally. Although the DOH had expressed some concerns about the design, it ultimately approved it with certain conditions.
First, as Whelan pointed out, the drainage improvement project was a massive undertaking — so massive that it defied the landfill’s standard solid waste permit condition that any work on surface water management features be completed before the rainy season.
Specifically, the permit requires Waste Management to report on an “annual inspection of surface water management features and facilities, together with a description of required maintenance and changes, which shall be completed by September 1 of each year.”
Even so, the permit also acknowledges the fact that during construction, there may be times when there are no means to convey storm water around the landfill or there is a storm so big that it overflows temporary drainage structures into cell E6.
The permit required Waste Management to cover pocket areas with a geomembrane sheet and to put in place pumps and other necessary equipment before such a rain occurred.
Before even constructing cell E6, Waste Management was supposed to have determined the quantity of sheeting and the size and number of pumps and other equipment deemed necessary, and to stage those materials for immediate use to prevent runoff from entering cells and eroding landfill cover.
Apart from the work on the drainage project lasting well into the rainy season, there was the fact that a 2003 expansion of the landfill left engineers with little room, and therefore, little choice but to eliminate drainage features that might have prevented overflows.
A storm water pond to control silt and debris from the upper part of the landfill was supposed to have been built after the DOH approved a solid waste permit in 2003 allowing for a 14.9-acre expansion. Years after the DOH had repeatedly asked Waste Management for a construction schedule for the pond, Waste Management informed the agency that it would not be built because it did not fit within the LUC’s special use permit boundary.
According to a 2009 report on what Waste Management describes as the Western Surface Water Drainage Project, the open drainage channel that diverted flows into the reservoir at the bottom of the landfill was fitted with about 5,200 feet of pipe and backfilled to make room for an extension of the landfill’s West Stability Berm and temporary stockpiling operations. Not only did that berm replace an open flow channel with the pipe that clogged during last winter’s heavy rains, it also left no room for the storm water pond.
A November 2009 report on the drainage project by GEI Consultants, Inc., notes that using a pipe to convey runoff in steep sections “also enables use of smaller, more economical pipe sections.” It adds that constraints of the site “preclude the use of other conveyance system alignments or energy dissipators … to reduce the overall grade and flow velocity.”
As to Whelan’s statement to the LUC that the project had been proposed a decade ago, that wasn’t quite true. Over the years, it seems the city and Waste Management could not keep designs for the project straight, submitting to the DOH one set of revisions after another. As late as 2008, drawings for the drainage system still included the pond that they claimed earlier could not be built within the permit boundary.
Complete drawings for the drainage project had not been submitted by September 2009, two months before construction began. On September 25, DOH Solid and Hazardous Waste Branch chief Steve Chang notified the city and Waste Management that their Western Drainage Project report was incomplete and the design submitted contained no provision for dissipating high velocity flow.
On December 2, Chang again pointed out deficiencies in drawings that had been submitted. They did not include enough information on how the drain pipes would be supported and on how the different components downslope of cell E6 would be connected.
What’s more, the designs submitted conflicted with each other and didn’t make sense to Chang.
For example, he wrote, “The installation of such a large (7 feet high by 12 feet wide) trench with pipes under the base liner was unexpected, and raises concerns including but not limited to the ability of the temporary storm water drains to handle 25-year 24-hour storm flows. We assume that this portion of the storm water system will be in operation before the entire western drainage system is constructed.”
He added that the pipes being used “may not be adequate to handle peak storm flows without an overflow capability. Please include the headwall design and explanation of how overflows will be avoided during peak flows in the updated drawings.”
By the time the DOH approved a new solid waste permit for the landfill last June, it appeared to have received an acceptable design in January, two months after construction had already begun.
— Teresa Dawson
Volume 21 Number 8, March 2011
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