Nicholas Brown – 2016 Parliamentary Question to the Department for Environment, Food and Rural Affairs
The below Parliamentary question was asked by Nicholas Brown on 2016-01-25.
To ask the Secretary of State for Environment, Food and Rural Affairs, what information her Department holds on the distribution of nitrogen and phosphates in the English river system since recent flooding; and what assessment she has made of the potential effect of that distribution on the natural environment.
Rory Stewart
The Environment Agency records the concentrations of nitrates and phosphates at thousands of locations across England. It monitors on either a monthly or quarterly basis over the course of the year. The January data should soon be ready for compilation. Many of the December samples were taken before the heavy rain so analysis of the data is still being carried out.
Heavy rainfall events, such as those experienced in the recent floods, generally cause an initial flush of nutrients from agricultural land and urban drainage systems to rivers.This causes an increase in river nutrient concentrations which then falls away due to dilution by high river flows.During floods, large amounts of nutrients are washed down rivers into coastal waters. If this occurs in summer it can trigger algal blooms, feeding on the nutrients. In winter, the effects are not generally significant as the reduced sunlight and colder water temperatures mean that algae do not grow.
