OSHA requires Job Hazard Analysis (JHA) to commence immediately prior to the job. Alaska has unique workplace challenges. OSHA directs.. “It is very important to look at the entire environment to determine every conceivable hazard that might exist.” Engineering in Alaska requires following many regulations; workplace safety at the top of the list.
Electric fencing is mandatory when in close proximity to the Kodiak Brown Bear. Kodiak bears are the largest in the world. A large male can stand over 10′ tall when on his hind legs, and 5′ when on all four legs. They weigh up to 1,500 pounds. There are about 3,500 Kodiak bears; a density of about 0.7 bears per square mile on Kodiak Island.
I first arrived in Kodiak back in the 1980’s as District Engineer for the State Department of Environmental Conservation (DEC); in charge of the Kodiak DEC office. Since that time I have had the good fortune of finding work around the islands. Icicle Seafoods (ICI) requested engineering assistance for a new wastewater treatment plant and discharge permit. Working around a seafood plant in bear country requires vigilance.
ICI operates a fish processing plant in Larsen Bay, on Kodiak Island. This cannery site has been used for about 100 years. During the short fishing season from May to September, the population at the fish processing plant swells to almost 300 people. Preliminary inspections revealed a new treatment plant was required. We selected a new treatment scheme that had been successfully utilized at Denali Canyon Lodge.
The summer work force is housed on-site, with an infrastructure that supports the workforce. Utilities include drinking water, and wastewater treatment and disposal. The DEC water quality standards, drinking water regulations, and wastewater regulations require certain standards to be met by these on-site utilities.
DEC requested a computer model of the mixing zone and location of the outfall line. This computer model would be cross-checked with conventional mixing equations. The outfall line was extended to 850′ from the process facility. The discharge line extends into the channel current to a depth of 2.5 m @ MLLW. Model input parameters included:
- Port Diameter @ 6″
- Port Elevation @ 1′
- Vertical Diffuser Angle @ 0°
- Horizontal Diffuser Angle@ 90°
- Number Of Ports @ 1 (actual ports may increase due to pipe perforations)
- Acute Mixing Zone @ 15 m
- Chronic Mixing Zone @ 50 m
- Port Depth @ 2.5 m
- Effluent Flow @ 0.025 MGD
- Effluent Salinity @ 0 psu
- Effluent Temperature @ 15° C
- Coliform Effluent Concentration @ 20 colonies/dl
- The Mixing Zone Ambient Depth Was Run Between 0.5- 2.5 m
- A Current Speed @ 2 Knots
- Current Direction Of 0° – 340° (outgoing tide) & 160° – 180° (incoming tide)
- Ambient Salinity @ 33 psu
- Ambient Seawater Temperature Between 40- 45° F
- A Background Concentration Of 0 contaminant
- A Coliform Pollutant Decay Rate Of 80/sec
- A Default Value Of 0.0004 Far Field Diffusion Coefficient Was Utilized
- DO Effluent Concentration @ 2 ppm
- A Background DO Concentration Of 10 ppm
- A Pollutant Decay Rate Of 0
The computer model produced a graphical and text output. The following general conclusions were determined:
- The plume elevation remains subsurface at a constant level
- The plume remains in a relatively narrow band parallel to shore
- A dilution factor of 500 is achieved 30 meters from port
- An incoming tide & outgoing tide will produce the mirror image mixing zone
The new wastewater treatment plant was designed as an activated sludge system using Moving Bed Bio-Reactor (MBBR) rechnology to enhance treatment capability. The new wastewater treatment plant is a product of EEC North America LLC. The wastewater treatment plant was sized for 25,000 gallons/day. Plant effluent is disinfect by UV prior to outfall.
“Make Work Fun” is my company motto. My chief technician/electrician Hans Eng accompanied me on nearby deer hunt. A campfire reduced the impact of the cold.
We camped out in bear country. Fresh bear tracks were visible in the snow nearby.
NorthRim Engineering 