Ordinance No. 19795 - Laserfiche WebLink

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An onsite air-quality test, in which measurements were taken for six hours a day under variable and uncontrolled weather conditions on four consecutive weekdays (Friday, March 1, and 11onday-Wednesday, March 4-6), from two sites, one due east of the Neste plant at the eastern edge of the proposed industrial buffer, and the other in the residential area just north of the buffer area, detected no more than .001 ppm. average exposures on any day, using the most sensitive testing methodology available. The highest projected concentration in LRAP A's model occurs right next to the plant on the western side of the 100-foot railroad right of way, over 500 feet from any potential residential use, only under specific wind direction, wind speed, and air stability conditions. This level is approximately one-half the level to which workers may be exposed continuously for eight hours a day, 300 days a year under the Federal Occupational Health and Safety Act (OSHA). The OSHA standard is 1.2 parts per million, or 1,500 micrograms per cubic meter, compared with the measured .001 ppm. or < 1 micrograms/cubic meter actually measured in the monitoring tests described above. The highest projected concentration occurring outside the proposed buffer area, according to LRAP A's models, would be on ly one thi rd of the eight-hour, 300-day-per-year OSHA standard. Furthermore, these exposures would, according to the model, occur with far less frequency than the daily exposure assumed by the OSHA standards. For example, the highest concentration on · the site, which occurs at the west side of the Burkland property next to the railroad right of way just east of the Neste plant, occurs only about one percent of the time, compared to the 8-hour daily exposure of double that concentration permitted for workers at the plant site. LRAPA's model assumes that the wind flows generally from west to east toward the Springwood site about 25 percent of the time. The rest of the time the wind wiII be blowing the plant's emissions in other directions. The most common condition on the site will be a zero concentration, because the wind will be blowing in another direction. When the wind is from the west, . concentrations at any given distance will often be at or near zero, and wiII only occasionally and briefly approach the highest concentrations, whiclrthemselves are well below the OSHA standards. The most frequent combination of west-to-east direction and any given air st,ability condition is about 13 percent, which is to say that about 13 percent of the time the wind wiII be flowing generally west to east under stability condition D. The highest concentrations projected for the entire site occur when the wind is at one mile per hour under these conditions, or about 8.5 percent of the time that C\ll other conditions are present. Eight and a half percent of 13 percent is 1.15 percent. ~ ' 4