Meeting/Event Information

REGISTRATION

The webinar link for the March Branch Techncial Session 2 is: https://register.gotowebinar.com/register/7414717603048817164

TECHNICAL SPEAKER:

Stan Williams, P.E., Senior Vice President, HDR, BIO

TOPIC: San Jacinto River Authority's Surface Water Treatment Plant

In 2007, the Lone Star Groundwater Conservation District (LSGCD) established rules that limited groundwater withdrawals to 100,000 acre-feet per year in Montgomery County, TX. At that time, groundwater permits had already exceeded the withdrawal limits and growth in the county was anticipated to result in aquifer drawdown, and potentially water shortages. An alternative drinking water supply was required to provide a safe and reliable drinking water source to the residents of Montgomery County, TX. In response to the LSGCD rules, SJRA stepped up to plan and implement alternative water supplies to assist many of the water suppliers in Montgomery County in meeting the LSGCD rules. Although, the rules compliance strategy included a multi-pronged approach, a new surface water plant was a key strategy for rule compliance. The SJRA headquarters is located on the southern backs of Lake Conroe and SJRA had access to water rights in the lake.

In 2009, SJRA selected HDR, Inc as their surface water plant engineering firm. Research of historical Lake Conroe water quality information was very limited and water treatability information did not exist, especially in respect to the EPA’s Safe Drinking Water Act Rules and Regulations. A water quality sampling program was initiated, bench and pilot scale treatability programs were conducted. These studies resulted in process selections that included high rate clarification, low pressure membrane filtration, granular activated carbon adsorption, disinfection with free chlorine and disinfection byproduct stripping. This multi-barrier approach provided a robust and flexible treatment of the Lake Conroe Waters.

Less than a week prior to startup, an historic rainfall event, significantly changed the water chemistry and treatability of the water in Lake Conroe.  This resulted in treatment challenges and nearly heroic efforts by SJRA to keep the plant in compliance with drinking water standards, meeting customer demands and complying with LSGCD rules while adjusting the treatment processes to address the changing water treatability in Lake Conroe.

This presentation walks through the planning, design, process challenges, and optimization efforts that were performed to meet the needs and expectations of SJRA, its customers and the LSGCD.