1. Are you aware of any regulation (in your area) on peak particle velocity required to protect structural integrity of adjacent structures (e.g. watermains/sewers) during pile driving? We are currently evaluating if our 5mm/s PPV requirement at the trunk sewers/watermains is reasonable. According to some sources,PPV of 50mm/s will ensure that no structural damage to surrounding structures will occur during piling?! 2. Do you think it is much more expensive to do piling under 5mm/s than under 50mm/s restriction?