A new approach to wastewater sulfide data collection is presented. The use of auto-samplers in conjunction with chemical fixative and preservative for collecting sulfide data was demonstrated during a large-scale pilot study conducted by East Bay Municipal Utility District (EBMUD) in July-September 1996. This new approach evolved from EBMUD odor pilot study experience and the realization that the dynamics of sulfide generation in an interceptor system require extensive data collection in order to draw meaningful conclusions. Data collection by the conventional grab sample and field analysis approach requires a significant manpower commitment and is not feasible for large scale pilot studies. The pilot study conducted by EBMUD consisted of wastewater characterization and chemical testing along a 16 km (10 mile) stretch of urban interceptor with flows ranging from 0.04 m3/s (1 MGD) to 2 m3/s (45 MGD). During the 10 week study 24-hour profiles were collected at 12 locations for a total of 4500 wastewater samples. In order to determine the accuracy of this new approach a quality assurance/quality control (QA/QC) program that included the analysis of blanks, duplicates, spiked samples and control standards was implemented. In addition, several tests were conducted including: evaluating the effect of holding time on fixed samples, examining the effect of fixative on grab samples, comparing results from field kits with results from lab procedures on fixed samples and comparing grab sample technique to auto-sampler technique for sulfide loss. Results from these tests indicate that this new approach is more accurate, more cost-effective and safer than the conventional grab sampling and field analysis approach.