Pollution Risk And Health Risk Assessments Of Phreatic Water In Songnen Plain

Groundwater is crucial to water resources due to its quality have a great impact on local production and life,social development,and the ecological environment.Songnen Plain is located in the hinterland Northeast China,which in a cold-temperate continental monsoon climate zone with semi-humid and semi-arid condition.It is an important place with machine building industry,petroleum energy,and commercial grain production.There is a large aquifer system in this research area and contains multiple sub-aquifer-system from the Cretaceous to Paleogene,Neogene,Quaternary.The groundwater resource is valuable in the case of regional water supply and irrigation.This paper selected the unconfined aquifer system as the target aquifer.Not only water chemistry characteristics and current quality situation,but also the intrinsic vulnerability,pollution risk and health risk of unconfined aquifer is studied in this research.This is significant to protect regional groundwater resource and ensure drinking water insurance.The details of this paper are shown as follows:At first the chemical characteristics and current quality situation of phreatic water is analyzed combined the area topography,regional geology,hydrogeology and other features by classical DRASTIC model.Then,the groundwater intrinsic vulnerability assessment index system is built to evaluate regional intrinsic vulnerability and identify the performance status of intrinsic vulnerability in unconfined aquifer.The regional pollution sources load risk is first analyzed based on land use classification,and the probability of groundwater pollution after superposition is gain combined the result of intrinsic vulnerability evaluation.The seriousness of groundwater contamination is got then based on the evaluation of quantity value and quality value of regional phreatic water.Furthermore,regional pollution risk classification is obtained based on the evaluation of quantity value and quality value of regional phreatic water,superimposed probability and seriousness of groundwater pollution.At last,the corresponding prevention advices are proposed due to its significance to phreatic water pollution.Based on phreatic water pollution risk assessment,the US EPA's typical"four-step" health risk assessment model is selected in order to research the influence degree and damage probability of phreatic water environment to human health.The established model,which analyze toxic heavy metals and "three N 'health risk quantitatively,provides scientific basis for regional drinking water safety and water environmental protection.