The Little Canada City Council notes are always a little depressing. After years of monitoring our city’s management, not thinking about the direction our city is heading for a few months has been relaxing. I've been out of state for a while and this is the moment I have to catch up on the Little Canada City Council meeting notes regarding our lake and neighborhood. Here's a scattering of topics that have come up over the last year:
Nothing new, so far, regarding any of the Savage Lake or I35E noise issues. Conversations about MNDOT’s noise barrier constructions along the new, widened I35E corridor have been notably absent. While I was in New Mexico, I received a call from a Star Tribune reporter regarding the comments I’ve made about the freeway noise in our neighborhood. After demoting/promoting me from an educator/engineer/acoustician into a “retired electrician,” the reporter briefly summarized our noise problems into a couple of sound bites. I guess some attention to our problem is better than none, but not much. The reporter semi-quoted me with, “’We’ve picked up 6 to 8 decibels [of noise] in our back yard just in the past few years,’ he [me] said. ‘When traffic is at its peak, you can’t have a normal conversation in our back yard. We have to shout at each other.’” Unfortunately, he left out the fact that the increases have put our backyards well above the sadly conservative and outdated OSHA guidelines well known to cause hearing damage and a variety of health problems.
To protect the noise-makers, OSHA and the EPA (and all MN state regulators) use “A-weighting.” A conveniently forgotten fact about the noise weighting curves is that they were designed to be used with specific noise levels; accounting for the fact that our hearing response is dependent on noise levels. Even more important to remember, all of the weighting curves were determined by sine wave testing, not broadband noise exposure. So, A-weighting was intended for “extremely low level” signals, –55dB unweighted and below. C-weighting is appropriate for 80dB and above noise exposure. The “advantage” of using A-weighting for everything is that A-weighting deletes/attenuates the low frequency content of the noise measurement, allowing for considerably more noise than is actually sensed (or causing damage) in the specification. If you look at the yellow graph line, vs. the red one, you’ll see that an A-weighted 30Hz signal can be ~25dB louder for the same weighting reading in C-weighting. The overwhelming majority of noises from roadway traffic are low frequency, especially at distance. While A-weighting makes reducing noise levels much easier for the noise makers and regulators, it is inappropriate in most public safety standards. If you still labor under the drunken delusion that government regulations hinder industry, you’ll have to ignore all of the above information to maintain your fantasies. Most regulations are intended to protect people with money and power from being sued by people without.
Stay tuned. I’ve started a 24-hour noise study in our backyard. I’ll post the results when I have some data to talk about.
“Brian Singletary indicated that his property taxes are doubling for 2014. Singletary asked the basis for this increase. He also noted that he lives near Highway 36 and expressed concern about the noise from this highway. The City Administrator noted that the increase in Singletary’s property taxes is the result of his new home reaching a fully taxed status for 2013, pay 2014 property taxes. The Administrator also explained that the City has no authority relative to sound walls along freeways, and this is an issue that is under MN DOT’s control. The Administrator reported that MN DOT has many standards in place that will trigger the construction of noise walls. He noted that given there are no changes proposed along this portion of Highway 36, therefore, MN DOT standards would not be triggered to put up a noise wall.”
“. . . Mayor Blesener noted that the City hired SEH Engineering to conduct a traffic study on LaBore Road from Edgerton Street to County Road D. The City Administrator presented the results of that study at the last Council meeting. . . Sohrweide reported that studies have indicated that if drivers feel a 4-way stop is unwarranted, in time they will only slow for the stop sign or do a slow roll-through. Sohrweide also pointed out that this area of LaBore Road is basically a residential through street. . . ” Which begs the question, if we know pointless multi-direction stops get ignored, what’s the purpose of the trio of stop signs at Jackson and Lake Streets? Can you say, “Tax collection disguised as traffic violations?”