Costs, timeliness and other operational factors are just some of the site implementation variables that may be difficult to control. These implementation variables include site access and permissions, electrical connectivity, security, communications, site operators and equipment. Costs may be estimated but there may be unforeseen factors that influence the outcome of the costs. An example was the performance of an analytical instrument utilized in the study. This instrument had both design and manufacturing issues that only became apparent after the instruments were deployed. The remedy for this situation was that the manufacturer performed an "in the field upgrade". Projects of this nature present myriad challenges both from a programmatic and technical perspective.
Access to sites owned by private citizens can be challenging. Adjacent property owners may understand the necessity of improving the state-of-the-science, benefiting the community at-large and have a desire to be a "good" citizen, but existing lease and financial issues are a deterrent to participation. In addition, liability, insurance compensation, hassle factor(s), and other real and perceived issues present obstacles to site access.
Electrical and communications companies have numerous requirements for obtaining their services. This process requires interactions with utility companies as well as local (i.e., county or city) inspections departments.