Is FOG Getting Too Much Blame for Sewer Blockages? - Trenchless Technology Magazine

Based on EEC's extensive Fats, Oils, and Grease (FOG) control and sewer system assessment experience, EEC's President - John Shaffer, was asked by Trenchless Technology Magazine to author an article summarizing many of the FOG control studies conducted by EEC over the past 7 years. The article candidly discusses the tendency that many sewering agencies have to blame a large percentage of their sewer blockages and SSOs on FOG. However, EEC has discovered that most sewer blockages related to FOG involve other issues that are often not properly assessed leading to increased long term maintenance costs and slower reductions in SSOs.

If you have any questions related to the article or EEC's FOG control studies or sewer assessment services, please contact John Shaffer.

National Groundwater Association Summit

EEC conducted a presentation discussing sampling techniques to evaluate the migration of groundwater into surface water bodies at the National Groundwater Association Summit in San Antonio, TX. The following is an abstract from that presentation.

In California's coastal areas, it is not uncommon for a contaminant release to occur near a surface body of water. The majority of corrective action has focused on the impact of contaminants to inland aquifers. Often overlooked is the effect of contaminant releases from coastal aquifers to aquatic life and habitat. The amount of knowledge and expertise in this field is limited and there are no established technical procedures, guidelines and/or methodologies to monitor the impacts of contaminant releases and plume migration from coastal aquifers into ocean, lakes, or estuaries.

Ocean sampling was performed at a site with a known contaminant release to shallow groundwater adjacent to the Pacific Ocean. Groundwater flow patterns suggest that groundwater could flow seaward. The goal of the sampling was to determine if, and to what extent, an onshore contaminate release into shallow groundwater was impacting the adjacent Pacific Ocean. The sampling techniques utilized included collection of sub-sea floor sediment pore water samples and near-sea floor discrete depth grab samples. The sub-sea floor sediment pore water sample was collected by inserting a sampling probe into the sea floor sediment at the approximate elevation of the groundwater/ocean water interface. The second sampling technique consisted of collecting a grab sample by lowering a discrete depth water sampler.

EEC evaluated both techniques and determined that the sub-sea floor pore water samples contained contaminant concentrations that were consistently higher and were detected more frequently than the grab samples collected 6 inches off the ocean floor at the same location. The grab samples still remained useful in determining the presence of contaminants and effects of dilution.

The majority of ocean sampling currently conducted consists of collecting grab samples. Grab samples can produce useful data; however, EEC believes that pore water samples provide a more accurate indication of contaminant migration from terrestrial to aquatic systems.

If you would like more information regarding this topic please contact Mark Zeko.