According to a study performed by Lisa Schweitzer, “transport spills toxic waste transporters, such as trucks generally cluster near origins more than destinations." In the study, Schweitzer observed the amount of toxic waste that is spilled during transportation and the area where spills are generally located. If intermodal facilities and transfer points are considered origins, Laidlaw Environmental would qualify. Furthermore, the hundreds of trucks that transport toxic loads travel in and out of the community every day. Given the results of Schweitzer's study, the residents of nearby communities (Buttonwillow, especially) are at the highest risk of experiencing side effects from the spills. Generally, spills occur as a result of human error, in which the load was packaged incorrectly or the driver experienced a vehicle accident or some other force which allowed for the leaking of toxins.