The sound walls are reducing the sound significantly for the neighbors.
by Patricia Schallert
“The recent noise being caused by conductor casing installation, is essentially pile driving at 3 beats per second. It is admittedly very loud, but it is as the City had expected and the sound wall is mitigating the situation significantly. This step is absolutely necessary for the drilling process and is currently about 1/3 completed. The loud noise should continue intermittently over the next two weeks”. Steve Mimiaga, Project Manager for City’s Construction Management team
One of the most important pieces of heavy equipment being used on this project are diesel motor driven air compressors to facilitate the conductor casing installation. Compressed air is vital and is being used in the construction of the VenturaWaterPure Outfall Project. “The City has been preparing for the use of this type of equipment for the project for well over a year” said Steve Mimiaga. Two sound studies have been undertaken by the City. And this particular piece of equipment is necessary to get those steel casing pipes diagonally into the ground. The project success is dependent on this process being done correctly.
The next steps of the project, the actual horizontal directional drilling (HDD), should not cause noise anywhere near this level. The HDD process requires multiple diesel motors running simultaneously for each of the three HDD headings: (1) from Marina Park toward the Harbor side, (2) from the Harbor side toward Marina Park, (3) from Marina Park to offshore. Each of the three HDD headings need multiple motors running for the drill rigs, drilling fluid mixing and pumping systems, drilling fluid recovery systems, and motors for heavy equipment moving heavy components around the site, like the hundreds of steel drill stem segments needed to advance the drill tips. The sound wall is expected to significantly mitigate these noises that will only occur between 7 am and 5 pm Monday through Saturday for the next few months. Again this part of the process is not expected to cause excessive noise impacts to the neighborhood.
During the next two weeks the compressor driven conductor casing noise will be intermittent as the crews need to stop every ten minutes or so to make adjustments and to make sure the pipes are going in the correct position. The noise will be intermittent over 3 to 5 days per heading depending on how well things go.
Steve and his team have been working long hours over the past weeks to prepare for and address community concerns. Noise levels are monitored by decibel meters and recorded on a daily basis throughout the project zone. Vibration sensors are installed throughout the neighborhoods on both sides of the Harbor crossing and recording data 24/7. Steve’s team monitor these sensors which will provide text message and email notifications if any alarm set points are exceeded. Steve reported that none of the Marina Park area sensors have alarmed so far in the process.
This project is very complicated with many intricate engineering and construction details to consider for every step. Steve explained that there are many-many critical activities that must be done a certain way and there is little wiggle room for mistakes. Steve notes that the City and the entire construction team are very appreciative of the patience and understanding from the public
