According to our friends at CommLawBlog, the FCC has revised its Rules with respect to a broadcaster’s certification of compliance with the Commission’s human exposure guidelines to non-ionizing electromagnetic radiation (RF) in its license renewal (Click here to see their take). In past renewal cycles, the broadcaster was required to submit a technical statement from an engineer, showing calculated or measured compliance with the RF exposure limits. In this round of renewals, a broadcaster can simply check a box on the renewal form that indicates that the RF environment surrounding the transmitter site has not materially changed since the last renewal cycle.
For a stand-alone broadcaster at a particular transmitter site, this is a no-brainer. Unless the station has changed its transmission facility since the last renewal and there has been no construction of residences, commercial buildings or tower structures in the vicinity of the transmitter site, there should be no change in the ground-level RF situation. If changes have been made to the transmission facility or if structures have been constructed in the vicinity of the site, new RF calculations should be made in order to ensure compliance with the FCC’s RF exposure Rules.
Most broadcasters operate at sites where there are other broadcast antennas. Such a complex RF environment requires more careful consideration. If there have been no changes to any of the broadcast facilities that have been operating there since the last renewal and there have been no additional broadcast facilities constructed at the site or an adjacent site, and no construction of new structures within close proximity to the transmitter site, the “No Change” box can be checked on the renewal form regarding RF certification.
Lately, the FCC has been ramping up its on-site inspection of stations that are believed to be exceeding the RF exposure guidelines. If the FCC finds that a station is indeed exceeding the allowable limits, the fines are severe and the Commission requires immediate rectification of the situation (including going off the air until an effective solution can be determined). If an inspector finds an area surrounding a particular transmitter site that exceeds the human exposure guidelines, the FCC considers a station liable for fines and mitigation techniques if its contribution to the RF situation in the area of concern is more than five percent (5%) of its particular guideline value.
Let’s say that you operate a broadcast antenna in an antenna farm. In a particular area of the transmitter site, the total RF from all sources at the time of last renewal cycle was 97 percent of the allowable standard. Let’s also say that the RF contribution from your station was 50 percent at that spot. Suppose that last year, a new FM station went on the air at the site. In the area of concern, the RF level is now 120 percent, well over the FCC’s allowable limit. If an FCC inspector measures the RF level in this spot, the Commission would fine your station and require you to take remedial steps to bring that area into compliance. And you hadn’t made any changes to your operation.
One other point regarding RF exposure needs to be made here. The FCC has two different exposure standards. The standard for public areas is five times more strict than it is for “controlled” sites. The definition of a controlled site has two requirements. First, it must be inaccessible to the public. For broadcaster’s that operate from a building rooftop, all points of entry onto the roof must be locked. For tower sites, this means a chain link fence with a locked gate surrounding the transmitter compound and tower. A gate across an access road is not sufficient if hikers, bikers and/or users of ATV’s can reach the site. The second and most overlooked requirement is that all those that access the transmitter site must be trained in RF safety practices. This applies to HVAC mechanics, window washers (for building sites), electricians, janitors, waste removal personnel, food service personnel, and, of course, all station personnel. The onus is on all of the broadcast users of a particular site to make sure that all contractors and employees that access the site have such training, otherwise the Commission will deem the site “uncontrolled” and the public RF exposure standard will apply.
If you have had a power density survey performed at your site, review the report and make sure that nothing has changed at the site with regard to the stations that operate from the site. Check and make sure that any RF warning signs that were installed are still visible. And, check to make sure that fencing and locks on gates are intact.
Finally, if you have any doubts about whether or not you comply with the RF exposure standards, contact an engineer. We can perform calculations for your station as well as conduct power density surveys of broadcast sites. We have RF meters that can determine overall RF levels in specific areas as well as individual station contributions in multi-station environments. In addition, we provide RF safety training classes for those that need to access your site.
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