Many Southwest Florida utilities use the Floridan Aquifer System (FAS) as the source of raw
water for their drinking water production. Over the last decade several utilities have turned
to this source instead of shallow, freshwater aquifers, which suffered from reducing water
levels and degraded source-water quality. In South Florida the FAS contains large quantities
of brackish groundwater with good and uniform quality, is protected from human influences
by overlying confining layers and is therefore the preferred source in areas of limited fresh
groundwater supply. The City of Cape Coral was one of the first cities to convert to the FAS. Due to rapid population growth, the City has begun a sizeable Utility Extension and Facility
Expansion Program to meet these needs. While keeping pace with this rapid growth, the City will
also increase the percentage of population served with drinking water via an accelerated
Utility Extension Program. Currently 71% of the population is served and this will increase
from 85% in 2015 to close to 100% in 2020. Cape Coral is a pre-platted community that
relies on domestic self-supply in areas not served by the Utility system. The potable demand is anticipated to increase from the current 14
MGD to 29 MGD in 2015. The expansion of the existing Southwest Reverse
Osmosis Water Treatment Plant (SWRO WTP) from 15 to 18 MGD is currently underway,
to meet short-term needs. In addition, the construction of the new North Reverse Osmosis
Water Treatment Plant (NRO WTP) with an ultimate capacity of 36 MGD, to meet the longterm
demands, has commenced. The first phase of the NRO WTP has been designed for a
capacity of 12 MGD and will be operational in early 2009. The second phase providing an
additional 12 MGD of treatment capacity needs to be operational in 2015. Following the experience at the SWRO WTP and supported by groundwater modeling, the
raw water quality is expected to deteriorate over time. The main contributor to this is that a
large percentage of the recharge to the production aquifer is through leakage from
underlying, more saline aquifers. The raw water deterioration requires special design
considerations for the NRO WTP. This paper presents a summary of the hydrogeology of
the FAS, explains the background and concept of changing aquifer conditions over time and
will present the features included in the design of the NRO WTP to cope with the
deteriorating raw water quality. Many water utilities in Southwest Florida using brackish
groundwater are dealing with the same issue. Therefore this case study is a typical
representation of the challenge of the Region's water supply. Includes 13 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 2.3 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 16 |
| Published : | 03/01/2007 |
