Collier County Wins WateReuse Award of Merit for 2009
Diversified Potable Water Supply Portfolio will Accommodate Growth
(Hollywood, FL – July 28, 2009) – The Collier County (Florida) South Regional Desalination Plant Expansion and Wellfield Expansion, designed by Hazen and Sawyer, has been chosen as one of six winners of the 2009 WateReuse Award of Merit, from among more than 50 nominations. The WateReuse Awards Program recognizes excellent water reuse and desalination projects and practitioners that advance reuse, have a new reclamation twist, or have made significant contributions to water reuse.
In 2005, the County began design and construction of a major expansion to the South Regional WTP reverse osmosis (RO) facilities, including a both a 20-mgd South RO Wellfield and a 12-mgd RO Treatment Expansion. The treatment expansion was placed into operation in 2007, and the wellfield expansion has been placed into service in phases from 2007 through 2009.
The population of Collier County has increased approximately 65% over the past ten years, and this growth, which is projected to continue, has produced tremendous stress on both water and wastewater infrastructure. Much of the low-cost, easy-to-treat shallow surface water supplies are tapped or unavailable due to concerns over saltwater intrusion and degradation of environmentally sensitive areas like the Big Cypress Basin.
As a result, Collier County has constructed a total of 28 mgd of brackish water supply and treatment facilities since 2001. Initially, the County constructed the South RO Wellfield (42 wells), a 20-mgd RO treatment facility, and two concentrate disposal deep injection wells. The ultimate goal was to have a mixture of surficial water (i.e., fresh water), brackish water, seawater, and reclaimed water to meet water demands. Future plans include providing a raw water blend ratio of approximately 40% fresh water and 60% brackish water to meet potable demands. The demand balance will be provided for by reclaimed water.
In addition to these brackish water facilities, the County has recently constructed and placed into service 2.0 mgd of seawater RO treatment skids to treat high-salinity brackish water from two high-production wells that have experienced increasing levels of chlorides, and has installed several additional “reliability” brackish water dual zone wells.
An important issue facing the County when it constructed membrane WTPs was the disposal of concentrate. Surface discharge is typically not permitted in Florida. To address this issue in an environmentally friendly manner, the County opted for disposal via deep wells, whereby reject water is injected into the seawater formation several thousand feet below land surface.
For more than half a century, Hazen and Sawyer has focused on two things: providing safe drinking water and controlling water pollution. Our range of services encompasses the planning, design, and construction management of water and wastewater-related projects – from clean water treatment, storage, and distribution to wastewater collection and treatment. Since our founding in 1951, we have grown in size to over 740 employees in 26 offices.