This product provides the median of monthly maximum turbidity values (in nephelometric turbidity units) for drinking water facilities by drainage region. Turbidity refers to the relative cloudiness of water, caused by suspended particles in water. The Survey of Drinking Water Plants collected this monthly maximum turbidity data for surface water sources from facilities reporting turbidity data for at least 10 months in 2013. These facilities served 24 million people and produced 4,091 million cubic metres of potable water from surface water sources in 2013. Source water turbidity was monitored continuously at 42% of these drinking water plants in 2013, daily at 34% of plants and less frequently at the remaining plants.

A chlorophyll fluorescence time series was collected at various locations around the coast of Vancouver Island, British Columbia, Canada for monitoring phytoplankton concentrations. A Wetlabs ECO fluorometer was deployed every few months on a schedule depending on season and sensor availability. The instrument hung by a chain attached to the side of the buoy, or dock, depending on location, and measured chlorophyll using the fluorescence emission at 695nm. The instrument also measured turbidity by detecting the scattered light at 700nm. The units had internal batteries and data storage and were programmed to make a group of 5 measurements every 30 minutes. A copper wiper covered the sampling window between groups of measurements to reduce fouling. Times are in UTC unless otherwise stated.