Today, in the absence of a national guidance and enforcement by the EPA, states, cities, and municipalities have had little or no guidance on writing competent and effective noise regulations. Since the EPA last published its Model Community Noise Ordinance in 1974, communities have struggled to develop their ordinances, often relying on copying guidance from other communities, and sometimes copying their mistakes.[10] Noise laws and ordinances vary widely among municipalities though most specify some general prohibition against making noise that is a nuisance and the allowable sound levels that can cross a property line. Some ordinances set out specific guidelines for the level of noise allowable at certain times of the day and for certain activities.[11]