HAMMER-Water Quality

Question

Hi, 
 I want to model the water quality parameters throughout the network during a transient event (by using a transient solver not EPS) and investigate the impact of hydraulic changes on the variation of water age. But I can not find the calculation type in HAMMER to change it to age or constituent, as in WaterGEMS. Can HAMMER model the water quality parameters based on the transient hydraulic solver? 
 Thanks, 
 Fatemeh

Tom Walski · Accepted Answer

The change in water quality in a distribution system during a transient even tis essentially negligible as long as there is no intrusion. A transient event seldom takes longer than a minute and not much changes in that time. 
 
The major water quality concern during transients is intrusion If there cross connections or leaks in saturated soil and the transient pressure becomes negative, contaminants can be pulled into the system. There have been a number of studies on this in recent years. This is why you want to ensure that pressures don't become negative during transients.

Craig Calvin · Answer

Hi Fatemeh, 
 Adding to Tom's advice, the following article covers negative pressures in detail. 
 Troubleshooting negative pressures at pumps, junctions, & other node elements