ARCHIVED REPORTS_XR0011649 - Laserfiche WebLink

Home Browse Search

1 -ely The total mass of contaminant addcd Dilution Factors tiring trine period r is The a%erage value apprommations given in this section are designed to giti e the estimated. I Mass added = JVhr = CLVcYh: (13) concentration at some downstream point as a 'where Y is the length of the discharge zone, and h function of some original concentration Co which is the a%erage water depth (figure 3) is presumably measured with inNentory wells at the The volume of water in the stream that solid waste boundary Perhaps a better wav to flowed past the discharge zone ober this time interpret these results is through dilution factors ' period - is Dilution is generally defined as the ratio of the Volume of water in stream = V%Vhr (14) total volume of a sample to the volume of effluent contained in a sample, and can range from one ' where V is the velocity of the stream, and W is the (undiluted state) to infinity (total dilution) stream width Since the volume of fluid added to Considering the upstream measuring point to the stream is VcYhr, the concentration in the substitute for the numerator of this ratio, and the ' stream will be " downstream point as the denominator, the working �--- - � equations can be interpreted in terms of dilution mass added CLVcYhr (15) factors Hence, for horizontal spreading (equation Csa`a"' total volume VcYhr + VWhr ' (2)J,vertical spreading [equation (5)] , and mining or, after some rearranging with recharge [equation (12)] , the ratio Co/CL provides a dilution factor For mixing with streams CL [equation (16)] , the dilution factor 1s Ci,/Cstrczrn Cstream 1 + (V IV}(W/Y) (16) Although it is not possible to rant: these dilution The important factor here is the group of factors in a consistent fashion, it is reasonable to expect that mixing with streams is the most ' terms V1VNcY, which will be a very large number important, and recharge by precipitation is because V/Vc is large, where V is the stream possibly more significant than spreading, at least in velocity and Vc -is the contaminant velocity in the humid regions of shallow ground-water ground-water flow at the stream aquifer boundary contamination The reciprocal of the dilution tactor is equal to the volume fraction of effluent and is referred to as a relative concentration The relative concen-tration can range from one (undiluted state) to zero (total dilution), and of course is also easily ' I : calculated and interpreted i Ali A_MODEL FOR VERTICAL AND c 'T i !`/ � HORIZONTALSPREADIN47 The E o —� Y t shortcomings of the average value approach discussed previously may tar outweigh ' tj I the simplicity of the calculations At best, these —~ I calculations provide a serniquantitanve measure of i the dilution potential for waste sites prior to ' 1 intensive investigations /I wu In this section we hope to enlarge on the a) i 11 scope of the study to provide a more realistic i ' model that may be useful in a regulatory-comph- Water ance schedule Once more, the aim is to focus on Table— — - _ w Some alternative boundary at which minimum ` ' performance standards must be maintained Hcnct-, h a sizeable degree of conservatism can be incorpo- rated In addition, this more realistic model focuses on maximum concentration levels which are of b ) greeter concern than averai;e.� in potential contam- Fig 3 Contaminant discharge into streams ination studies ' 308