The developer of the Palisades Estates subdivision is facing a $1.7 million fine for alleged environmental violations in connection to the October 15 landslide that caused sediment runoff in East Hagatna Bay and snarled traffic.

But Tasi Vista Development said they “stand by its record of responsible development and commitment to the highest standards” and plan to appeal.

The Guam Environmental Protection Agency has concluded their investigation into what caused the landslide, according to the agency’s Acting Administrator Glenn San Nicolas.

Both the Guam Department of Public Works and Guam EPA said that “the landslide was caused by a combination of extreme rainfall, uncontrolled overland flow from development, and lack of proper stormwater management controls,” as stated in a Notice of Violation and Order of Compliance published by Guam EPA.

But Tasi Vista Development will appeal the notice of violation, saying they are “confident that a thorough review of the factual findings from its inspections will confirm that the events on October 15 were caused by circumstances beyond its control and are not attributable to the Palisades development.”

According to Guam EPA, the developers said the basins were filled, “because most of the house pads in the subdivision had been completed and were being prepared for sale.”

San Nicolas alleged the modifications were made without the agency’s knowledge, and if they had asked, they would not have approved it.

The agency issued a stop work order the day of the landslide that required immediate actions to prevent further runoff and to stabilize the site.

The developers said they “immediately launched a comprehensive site inspection with its contractor and engineers. It also coordinated with GEPA to further develop a stormwater mitigation plan that has been installed and approved.” After that approval, the stop work order was lifted on October 28.

Tasi Vista said they will “pursue all available administrative avenues to appeal the notices of violations and seek a fair resolution to the matter. It remains dedicated to engaging in constructive dialogue with GEPA and DPW as the appeal process moves forward and looks forward to resolving these matters expeditiously.”

The Guam EPA Board of Directors are to hold a public hearing for the developers to present their evidence and argue their case.

Meanwhile, a similar extreme weather event is occurring this week. Emergency officials warned of heavy rain that could bring 4 to 8 inches through Friday, increasing the risk of flooding and mudslides.

When asked what mitigation measures are in place to prevent another landslide, San Nicolas said “in terms of the Palisades Estates subdivision, the mitigation plan that’s in effect [is] them complying with the stop work order [and] their own mechanisms to help address storm water run off the property. Guam EPA is also working with Homeland Security, who would be putting out press releases for rain events that may impact flooding and also mudslides.”