The Ascon Landfill Site stormwater management measures are in compliance with the Santa Ana Regional Water Quality Control Board (SARWQCB) permit. There were no exceedances of California Code of Regulations Title 22 criteria regarding chemicals of concern.

The results of outside professional laboratory analysis of stormwater sampling conducted following the significant storm events in late December 2019 have been provided to SARWQCB and the City of Huntington Beach.

Stormwater professionals for the Ascon project monitor long-range weather forecasting. The Site was inspected prior to the December rain storms and again following the storm events, including sampling following the protocol established by SARWQCB.

An update about actions taken during the December storm was shared on this website on December 30 at Below is additional information regarding stormwater management at Ascon.

Frequently Asked Questions: Stormwater

As part of the cleanup actions at Ascon, stormwater management plans and measures have been implemented since 2006 in compliance with State permits.

How does Ascon plan and manage stormwater?

A Stormwater Pollution Prevention Plan (SWPPP) is prepared by Ascon. Implementation of the SWPPP is overseen by a Qualified Stormwater Practitioner on the Ascon team. The SWPPP directs the management and monitoring of stormwater, the surface water generated from rain events. The SWPPP is enforced by the City of Huntington Beach and the Santa Ana Regional Water Quality Control Board (SARWQCB).

What actions have you taken to manage stormwater?

In advance of the 2019-2020 storm season and following the Site SWPPP, the Ascon team implemented these additional actions at the 38-acre site:

  • Installed a silt fence, a filter fabric stretched between posts driven into the ground, inside the barrier fence along the northern and eastern perimeters.
  • Maintained and installed additional sand or gravel-filled bags within the Site interior, as well as in perimeter areas.
  • Stabilized soils with an environmentally safe Posi-Shell®, an odor suppressant material that binds to loose soils and forms a thick crust.
  • Hydraulically applied wood mulch with a plant-based binder to form a protective cover over loose soils.
  • Stabilized areas of the Site with plastic sheeting.

What do all these actions do?

The goal of a SWPPP-regulated project is to limit the amount of sediment (soil/mud) in stormwater. Stormwater is authorized by permit to discharge into the municipal stormwater system. If stormwater is discharged, the Ascon team samples the runoff for multiple chemical constituents. Stormwater runoff is channeled into the City’s engineered French drain and directed to the City storm drain system, and is treated before discharge by the City. This is separate from Magnolia Street ponding, where stormwater may originate from multiple sources other than Ascon.

What are you monitoring for in stormwater?

In accordance to the Ascon SWPPP, stormwater runoff is monitored for pH, turbidity, volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs), pesticides, metals, hydrocarbons, ammonia and biological oxygen demand (organic pollutants). Action levels are determined by the SARWQCB. Sampling for 2019 and 2020 has shown Ascon is in compliance with the stormwater permit and levels below the stormwater action levels.

There was a large rain event the night of December 25, 2019, and a lot of water ponded on Magnolia Street. Did the stormwater measures work?

Yes, the stormwater management system worked as intended during the rain event.

In response to a resident’s inquiry, the SARWQCB Region 8 Enforcement Coordinator Chuck Griffin, PE, responded on December 30, 2019:

“The (Ascon) site has internal Best Management Practices that keep potential contamination from comingling with the storm runoff that leaves the site. I have been in contact with the Site QSP (Qualified SWPPP Practitioner)* as well as the site manager and they are performing the inspections and sampling in accordance with their Stormwater Pollution Prevention Plan.

The corner located at Magnolia and PCH notoriously floods which is not caused by ASCON [emphasis added] (undersized storm drain at that location). Based on soil sampling conducted this fall (basically non-detect for pollutants in the soil) we agreed to the plan to allow run-off to leave the site (areas that are not in direct contact with suspected contaminated areas). We asked for and it was agreed that sample would be taken of the stormwater that leave the site and analyzed for specific pollutants of concern. On Monday December 24 and December 27 sample were taken of the runoff from the site and we will be looking at those results to ensure we have appropriate protections in place for stormwater leaving this site.

We are unable to address the flooding that is caused by the undersized storm drain at Magnolia which most of the water that causes the flooding is from street runoff as well as other properties not associated with ASCON [emphasis added]. The measures that have been implemented so far appear to be adequate.”

*A QSP, or Qualified SWPPP Practitioner, must meet the certification requirements of and be registered with the California State Water Resources Control Board. The Ascon project team includes a dedicated QSP.

Is this how stormwater will be managed after the cleanup is done?

The ongoing oversight after this cleanup includes stormwater management which further protects the public and environment.

The Site will be graded, an engineered environmental cap and liner system will be installed, new storm drains and water detention basins will be constructed, and the Site will be planted with native vegetation to help prevent soil erosion. The engineered environmental cap and vegetation acts as a barrier and clean stormwater will drain into the City of Huntington Beach storm drain system.

Want more information?

Read our stormwater explainer under the Our Safety Commitment tab on this website at

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