column samples are collected monthly from 18 stations.
Nine outfall monitoring stations are located at outfalls for
the West Point, South, and Vashon treatment plants, the Alki and Carkeek combined
sewer overflow (CSO) treatment plants, the Elliott West and Henderson/MLK/Norfolk
CSO treatment facilities, and the Hanford/Lander and Barton CSOs. Seven ambient
monitoring stations are located throughout the Central Basin. Water samples are
collected from between one and seven depths at each offshore station, depending
on the total station depth. View a table of parameters analyzed at each depth
Two additional ambient stations, collected as part of the marine offshore program, are located in the
Duwamish River, just upstream of Harbor Island and at the 16th Avenue South bridge, with
samples collected from two depths at each station.
Laboratory analytes include
fecal coliform and enterococcus bacteria, chlorophyll-a and pheophytin pigments,
solids, and nutrients (ammonia, nitrite/nitrate nitrogen, total Kjeldahl nitrogen,
total phosphorus, and silica). Bacteria samples are collected from all sampling
depths at each of the outfall monitoring stations but only from the surface at ambient
monitoring stations, with the exception of the Quartermaster Harbor and Duwamish
River samples. Bacteria samples will be collected from both depths at each Quartermaster
Harbor and Duwamish River ambient station.
Currently, only in situ CTD water column profile data are available for
download through the web site. These data are available by visiting the
Offshore CTD Monitoring page and selecting a station from the map. Data
from discrete sampling depths (nutrients, bacteria, phytopigments, solids) may be
requested by contacting Wendy Eash-Loucks.