Khidir Hamad

Graduation Semester and Year




Document Type


Degree Name

Master of Science in Civil Engineering


Civil Engineering

First Advisor

Andrew P Kruzic


Tarrant Regional Water District (TRWD) pumps untreated raw water from Richland Chambers and Cedar Creek reservoirs in East Texas to provide water to several customer cities including Arlington and Fort Worth. TRWD adds chloramines to the pipeline to combat biofilm growth, that reduces pipeline capacity and increases pumping costs, and to control zebra mussels, that clog intake structure screens and the pump wet wells. However, addition of chloramines leads to the formation of N-nitrosodimethylamine (NDMA), a potent carcinogen, by reaction of chloramines with nitrogenous organic precursors possibly present in the raw water. NDMA formation presents a challenge to TRWD because potential regulation of NDMA and other nitrosamines will force TRWD and other utilities alike to seek treatment options. Because post treatment removal of NDMA is ineffective and expensive, the best strategy is to optimize conditions to minimize NDMA formation and to eliminate nitrogenous NDMA precursors in the system. This research examines the effect of preformed chloramines and chlorine to ammonia mass ratio on NDMA formation in the District’s current and future pipelines.


Civil and Environmental Engineering | Civil Engineering | Engineering


Degree granted by The University of Texas at Arlington