Tetra Tech, Inc.

10306 Eaton Place, Suite 340 Fairfax, VA 22030 phone 703 - 385 - 6000 fax 703 - 385 - 6007
DATE: November 14, 2008 TO : Paul Shriner, EPA FROM : Christine Wong SUBJECT: Substratum intake Introduction Tetra Tech conducted a limited impingement and entrainment (I&E) reduction substratum intake technologies intended to inform the development of information for the revised rule Tetra Tech performed general Web searches using combinations of search terms subfloor water intake structure s ys tem, desalination, seafloor, beach well, sea well, bed and basin

. Tetra Tech (Tt) also researched a proposed project at the Shoreham site Preliminary

Findings In general, the search yi eld ed detailed information. Desalination drinking water facilities industry utilizing subs tratum States, operation of desalination facilities ha 

### MEMORANDUM

10306 Eaton Place, Suite 340

November 14, 2008 Paul Shriner, EPA Christine Wong and Kelly Meadows, Tetra Tech Substratum intake s

conducted a limited search of Internet resources to identify size, cost, and impingement and entrainment (I&E) reduction performance data for facilities using substratum intake technologies (also known as filter beds)

. The information recovered

development of performance standards and supporting background rule

. Tetra Tech performed general Web searches using combinations of search terms subfloor water intake structure s ys tem, subsurface, substratum, cooling water, desalination, seafloor, beach well, sea well, impingement, entrainment, and infiltration Tetra Tech (Tt) also researched a proposed project at the Shoreham site in New York.

ed a moderate number of resources with a limited amount of Desalination drinking water facilities appear to be the predominant intakes in their operations. While extant in the United States, operation of desalination facilities ha s so far been concentrated in Europe, N identify size, cost, and performance data for facilities using tion recovered is performance standards and supporting background Tetra Tech performed general Web searches using combinations of search terms such as cooling water, and infiltration
in New York.

with a limited amount of

he predominant operations. While extant in the United r been concentrated in Europe, N orthAfrica, and the Middle East. Some non

- desalination drinking water facilities also use

subs tratum water intakes. At the present, the use of subs tratum intakes for cooling water intake structures (CW I S) is mostly in the design and pilot stage. Tetra Tech identified o ne facility that is s eriously considering using a substratum intake to supply its cooling water (see bel ow)

. Intake flow and intake structure type are the most readily available information; there is little information on cost and concerns regarding I&E of aquatic organisms. Most large desalination facilities use surface water intakes ; only a few of the world’s larger desalination plants use substratum or subsurface water intakes. In general, “ subsurface intakes are considered to be cost

- competitive for plants of capacity smaller than 1 million gallons per day

(mgd). ” 1 These faciliti es most commonly make use of vertical or horizontal beach wells, which are shallow shoreline intake wells that use the overl yi ng rock or sand layers as a filter medium. As of 2005, “ there were only four worldwide operational seawater reverse osmosis desal ination facilities with capacity larger than 5.3 mgd using beach well intakes. ” 2 For these intake structures, concerns regarding I&E of aquatic organisms are not ty picall y addressed; where they are menti oned, I&E is assumed to be zero and is considered to be part of the desired baseline performance of the intake design. There are studies and pilot projects being conducted to investigate the viability of subsurface or substratum CWI S. Earl y investigations have yi elded positive results, including 100% red

uction of I&E of aquatic organisms. 3 Only a few vendors appear to be working on substratum intake technologies for CWI Ss. At least one manufacturer is pursuing or has obtained patents for substratum technology intended for use as CWI S. Product and company

contact information is available for at least one English

- language manufacturer in Canada. Many desalination facilities using surface water intakes in the United States are sited, or planned to be sited , along existing power plants or other facilities with water intake operations, so the water withdrawals may be conducted through existing water intake structures. Poseidon Resources, a company that develops, invests in and manages water infrastructure projects throughout North America, is connected to m an y of the recent and ongoing desalination facility projects (using both surface and subsurface intakes) in the United States

. The attached chart details the main facilities , studies , and manufacturers identified in this search.

1 Voutchkov , N. 2005. SWRO desalination process: on the beach

– seawater intakes. Filtration & Separation (42):8, October 2005, pp. 24

- 27. 2 Pankratz , T. An Overview of Seawater Intake Facilities for Seawater Desalination

. http://texaswater.tamu.edu/readings/desal/Sea waterdesal.pdf ; Voutchkov , 2005. 3 EEA, Inc. 2005. Keyspan Generation LLC studies the substratum intake system: An Innovative water intake system for power generation facilities. Environmental Consulting Insights Newsletter . Spring, 2005.Shoreham

Tt contacted the New York Department of Environmental Conservation (NYDEC), 4 who would regulate the proposed intake. Kevin Kispert at NYDEC acknowledged that NYDEC had received an application for a substratum intake (including conducting a pilot study) but directed Tt to contact Energy & Environment Analy sts (EEA) who is the primary consultant for the project. On January

2, 2008, Tt spoke with Roy Stoecker and Jim McAleer from EEA regarding the proposal to install a substratum intake at the Shoreham Site whi ch has appropriate and ty pical geological conditions. 5 EEA has been working with Key span Energy (a National Grid Company) for several years and initially conducted a feasibility

study using existing technical, geological, and hydrological data. In order to operate a 400MW power plant, it was assumed that a withdrawal rate of approximately 170,000 gallons per minute (gpm) would be required. The study concluded that the aquifer could support such withdrawals, given a sufficientl y large intake field. The n ext step is to conduct a pilot study . EEA developed a proposal and, through a funding program from a combination of Key Span, LIPA and NYSERDA, the pilot study is scheduled to be conducted in the spring of 2008. Currently , EEA, KeySpan and LIPA are awaiti ng approval of several permits to begin the testing. EEA’s staff generally

assumes that the substratum intake will eliminate impingement and entrainment, as well as offer other benefits: reduced operations and maintenance costs, minimal downtime required at installation, and expected fuel savings in the summer. As of November 14, 2008, EEA’s website (via its sister company SI S Water Sy stems, http://www.siswatersy stems.com/) indicates that the pilot project wil l begin construction in the fall of 2008. Other projects are also under development.

4 On December 20, 2007. 5 This site is utilized by KeySpan for combustion turbine and diesel generation.Facility/Study/

Manufacturer Location Size (flow) Cost I&E reduction strategy/technology I&E reduction performance Long Island Sound Substratum CWIS Feasibility Study Long Island, NY Intake

- 700,000 gpm Significant cost reduction of ty pical CWIS costs Substratum Intake Structure to draw water from underneath the Long Island Sound 100% reduction
Initial Evaluation of the SWISS vs. Conventional Multimedia Pretreatment Techniques USA Estimated ~ 20

- 32% reduction of typical SWRO facility total costs Subfloor Water Intake Structure Sy stem (SWISS); no I&E technology mentioned 100% reduction
Long Beach Desalination Prototype Facility Long Beach, CA 300,000 gpd Design and construction phase of Under Ocean Floor Seawater Intake and Discharge Demonstration Sy stem 100% reduction planned
Elmosa Marine Works Ontario, Canada Max capacity

- 60,000 gpm;

intake flow

- ~ 0.3 fps “fractional cost” of other intake syst em s Offshore and onshore infiltration intake systems 100% reduction New Infiltration Intake System for Zebra Mussel Control and Larval Exclusion Maximum intake

- 3 m3 /s 30% or less of conventional intake systems Filtration bed intake system 100% reduction
Marine Coast Water District Seawater Desalination Facility Monterey, CA Intake

- 450,000 gpd; Produces

- 300,000 gpd Beach wells; no I&E technology mentioned Cirkewwa Reverse Osmosis Desalination Plant Malta Intake

- 4.9 mgd; Produces

- 2 mdg Beach wells; no I&E technology mentioned Pembroke Reverse Osmosis Desalination Plant Malta Intake

- 14.3 mgd; Produces

- 6.4 mdg Beach wells; no I&E technology mentioned Ghar Lapsi

- Reverse Osmosis Desalination Plant Malta Intake

- 6.3 mgd; Produces

- 2 mgd Beach wells; no I&E technology mentioned Kalaeloa Desalination Plant Honolulu, HI Planned intake

- 11 mgd; planned production

- 5 mgd Estimated at $45 million Deep basal wells; no I&E technology mentioned Bay of Palma Desalination Plant Mallorca, Spain Intake

- 11 mgd 16 vertical beach wells; no I&E technology mentioned Pemex Salina Cruz Refinery Mexico Intake

- 3.8 mgd Beach wells; no I&E technology mentioned Tampa Bay Seawater Desalination Plant Hillsborough County, FL Intake

- 44 mgd; Produces

-

25 mgd $75.5 million Co

- location with existing plant utilizing fine mesh screens No additional I&E opportunity created