1 Project No.: 0317.00.029.032 DISTRIBUTION

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Project Name: Steam Electric Rulemaking

TELEPHONE CALL RECORD

Conference Call Date: 1/2/2013 Time: 11:00 am EST

Company Name: Siemens Industry, Inc. Contact Name: Timothy Peschman, Adam Szczeniak,
and Jennifer Ellis

Phone No.: 651

- 638

- 1325

Name s : TJ Finseth and Shelly Schultz

GENERAL SUBJECT : Discussion of Merrimac k Station System Operation and Costs

TOPICS DISCUSSED AND ACTION TAKEN

The purpose of this telephone call w as for Eastern Research Group (ERG) to obtain information about the wastewater treatment technologies Siemens Industry, Inc. (Siemens) has developed for the treatment of FGD wastewater for the removal mercury and arsenic . ERG was specifically interested in the sorption media treatment technologies utilized at Public Service Company of New Hampshire's Merrimack Station . These systems include the SCU Adsorbent and the G FH® Media. The following provides a summary of t he details Siemens provided ERG with during the call.

SCU is a single use granular carbonaceous absorbent media that can be used for metals removal in many different applications. SCU selectively adsorbs dissolved metal cations including cadmium (Cd), trivalent chromium (Cr+3), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), and zinc (Zn)

. Mercury is the target ed

metal at the Merrimack Station. The media is stored in vessels that can be run in series or parallel. At the

Merrimack Station , there are t hree vessels installed in series

, where two are run together and one is in reserve (i.e., spare vessel)

. The system is set up in a way so that any two of the three vessels can be used in any

combination. Because the media is single use , there is no regener ation associated with the system

. Siemens designed the size of the vessels at the Merrimack Station such that the media would need to be replaced four times per year. Replacement of the media is determined based on target metal concentrations in the efflu ent wastewater. When the target metal concentrations begin to increase (i.e., lower removals through the system), then the media needs to be replaced. According to Siemens, at the Merrimack Station, the media in the first vessel needed to be replaced aft er approximately 3.5 months of operation. After the initial replacement, the second vessel has been operating for eight months and has not yet needed to be replaced. Depending on the flow rate and removals desired, the system can be set up such that multip le small vessels (e.g., 48 inch diameter) are used in the system and when the media needs to be replaced, Siemens would come and swap out the vessel with a new vessel. Otherwise, large vessels could be installed and when the media needs to be replaced, Si emens would come and vacuum out the used media and refill the vessel with fresh media.

At the Merrimack Station, the permitted maxim um effluent mercury concentration was set at 14 parts per trillion (ppt). Siemens designed the system based on an influent mercury concentration entering the media at 100 ppt. The system has been achieving low single digit ppt levels.

The GFH® Media is a granulated ferric hydroxide media that is used primar il y for the remov al of arsenic

, but it also provides removal of othe r heavy metals. According to Siemens, i t is best suited for arsenic removals from wastewater with low silica concentrations. Similar to the SCU media, once the GFH® Media is exhausted

, as determined by sampling results, the media is removed and replaced. S iemens suggested the GFH® Media has the potential for some selenium removal, if it is in the selenite form; however, Siemens does not market the2 GFH® Media for selenium removal. Instead, Siemens is developing a new technology consisting of a reactiv e media with a chemistry feed that is specific for selenium removal

.

During the conversation, Siemens indicated the success of systems with the SCU and GFH® Media are contingent on solids removal prior to running through the media. At the Merrimack Station , th ere is a chemical precipitation system and a three stage cartridge filtration system containing 3

- micron, 1

- micron, and 0.2

- micron pore filters prior to the sorption media vessels

. Th e cartridge filters are needed to remove very fine suspended

solids in th e wastewater so they do not clog the absorbent media.

Siemens stated that the i nitial capital costs for a system with SCU and GFH® Media vary significantly depen ding on the system’s features and requirements. S ie mens estimates that the capital costs coul d range from $200,000 to $2,000,000 , depending the flow rate, influent concentrations, and system configuration . Specific

costs associated with the Merrimack Station are proprietary; however Siemens p rovided some general cost estimates based their operatio ns. From April to December 2012 the system has processed approximately 10 million gallons at a rate of approximately 40 gallon per minute. Based on the replacement frequency observed at Merrimack, t he media costs for the SCU is approximately $2 per 1000 ga llons and the GFH® Media is $1 per 1000 gallons. There are additional costs associated with these systems

, such as operating and maintenance labor

and analytical monitoring/ sampling that are not included in these estimates. Siemens stated that the s ampling intervals would be dependent on permit requirements. Typically a new system would be sampled daily during the initial start up period and until a ll issues are worked out , but after that period, Siemens stated that samples would likely be collected once pe r week to confirm treatment.