Records Reveal Warning Against Building on Land Linked to Childhood Cancer Cases in Ladera Ranch

Officials were warned over 20 years ago not to build on land now struck by extremely rare childhood cancers, according to unearthed records. Handwritten notes on documents related to the abandonment of a historical oil well beneath Ladera Ranch in Orange County, California, indicated that further considerations were needed before construction. The memos have raised concerns about at least six cases of Ewing sarcoma diagnosed in the community between 2013 and 2024. Some community members suspect pesticides used on school property, while others point to a nearby landfill as potential causes, with health officials investigating possible links. The notes, marked in pencil on a Department of Conservation permit, state: "This well is not to be built over without further considerations." The final report was signed by state oil and gas supervisor William F. Guerard Jr., acting state oil and gas supervisor Kenneth Henderson, and deputy supervisor R.K. Baker when the well was sealed on February 26, 2002. The memos, written by engineer Floyd Leeson, do not explain the reasons for the warning or whether any further considerations were taken. Henderson stated in an interview that he did not recall the reasons for the notes but suggested that the well plugging may not have met current standards. The Department of Conservation mentioned that the notes could be a clerical error but did not clarify the need for them to be "put on final letter." While there is no evidence linking the abandoned well to the Ewing sarcoma cases, scientists are still uncertain about the causes of the disease. Karen Lincoln, director of the Center for Environmental Health Disparities Research at UC Irvine, emphasized the importance of understanding the concerns raised in the notes. She noted that abandoned oil wells can allow gases or substances to move toward the surface if not properly sealed. Lincoln highlighted the need for thorough examination of the records surrounding the Citrus Lane well before drawing conclusions. She stated, "There is an important distinction between a potential hazard and an actual exposure." Potential contaminants from oil wells can include methane, hydrocarbons, and benzene, some of which are associated with serious health effects. Lincoln also pointed out that exposure pathways could include air, soil gas, and groundwater. She cautioned against assuming a direct link between the well and cancer cases, stating, "We don’t know that the well is causing harm." Residents have expressed concerns about potential environmental health risks and deserve a transparent response. Ladera Ranch is a family-oriented community of approximately 24,000 residents that began developing in the late 1990s on land that was once part of the Rancho Mission Viejo cattle ranch. The first homes were sold in 1999, and old oil wells were abandoned as construction progressed. Residents have been seeking answers regarding the cluster of Ewing sarcoma cases, which disproportionately affect children and young adults. A UCLA study found geographic areas with high concentrations of the disease and called for further investigation into environmental risk factors, while cautioning that causality cannot be inferred. Parents in Ladera Ranch have expressed frustration over the uncertainty surrounding the potential environmental factors contributing to the cases. CalGEM advises against building over sealed oil wells to maintain access and reduce leakage risks, stating that wells sealed to current standards are less likely to leak, though there is no guarantee. The Post reached out to CalGEM, Henderson, DBM Developments, and health officials for further comment.