### MEMORANDUM

To: Debbie Ottinger, U.S. EPA

Cc: Sally Rand, Kirsten Cappel, U.S. EPA

From: Paul Stewart, Mollie Averyt, and Deborah Harris, ICF International

Date: June 28, 2010

Re: The potential role of gas suppliers in weighing residual Fluorinated GHGs received from industry in relation to subpart I, DD, and SS reporting requirements (EP-W-07- 0068, Task Order 68, Task 2)

The reporting requirements in the EPA Greenhouse Ga s Mandatory Reporting Rule Subparts I, DD, and SS (electronics manufacture, electric power system, and electrical equipment manufacture, respectively) require that facilities track not only the amount of fluorinated greenhouse gases (F-GHGs) received from gas suppliers but also the amount returned to t hem. Each subpart proposed the same monitoring requirement that scales (or other instruments) used to measure quantities of gas must be certified to be accurate and precise to within 1 percent of the true we ight (or of full scale in the case of subpart I).

While some electronics manufacturers do estimate the amount of gas consumed at their facilities using “heel” factors and purchases, many use an IPCC default heel factor and have claimed in their public comments that the proposed accuracy and precision requirement is not feas ible for the them to meet at their facility. Additionally, since electric power systems typically do not receive a credit for SF 6 returned to the supplier, it has not historically been standard proc edure for either the electric power system to weigh the cylinder to quantify the residual gas, or “heel”, or the gas supplier to provide this information to the utility. 1 Electrical equipment manufacturers have not specified via public comment whether they weigh returned cylinders or rely on suppliers to provide this service for them.

Gas suppliers already measure the gas they supply to their customers and provide that information to their customers; however, it is less certain whether gas suppliers pr ovide measurement services for the gas they receive back from their cu stomers as the heel left in “empty”, returned cylinders. Since one option for facilities to meet the stated requirements of the rule may be to have gas suppliers provide measurement services for reporters, the purpose of th is memorandum is to explore further the potential role of gas suppliers in weighing the returned amount of F-GHGs in order to help facilities comply with the stated regulatory requirements.

The goal of ICF’s research on this topic was to investigate:

• the weighing services gas suppliers provide;

• the cost of these services;

• the number of suppliers offering this service; and

• whether the services could satisfy the proposed regulatory requirements.

1 The exception has been utilities that have participated in EPA’s SF 6 Emission Reduction Partnership for Electric Power Systems. These Partner utilities have ta ken efforts to document the quantity of SF 6 returned to suppliers for voluntary reporting purposes.I. Correspondence with Industry

ICF contacted the following companies on the following dates: 2

- Airgas (Bob Mueller) June 3, 2010;

- AirProducts (Bob Ridgeway), June 4, 2010;

- 3M (Kurt Werner), June 13, 2010

Airgas Summary Bob Mueller of Airgas confirmed that any gas supplie d to customers by Airgas is weighed using scales, and the weight is provided to customers. Airgas also provides a service to customers of weighing how much residual gas is returned to Airgas in cylinde rs as well as maintaining records of these residual amounts. However, this service involves an extra f ee (the exact cost of the fee was not provided).

Mr. Mueller also stated their scales have accuracies of +/- 2 lbs of true weight and that the 1% of true weight accuracy requirement in the proposed rule is not feasible for Airgas. However, he did state that the recalibration requirements in the proposed rule are mo re feasible and that Airgas already meets those requirements. He mentioned that Airgas will be submitting a formal public comment to EPA on the proposed rule, and asked that EPA re views the public comment for mo re information (See Section II below). Since Airgas is not required to report emissions under the proposed rule, presumably their primary concern over the accuracy of their scales is whether they are capable of providing utilities with weights of returned gas that the utilities could then report under subpart DD.

Mr. Mueller said that he cannot comment on the specific services provided by ot her gas suppliers in the industry, but he does not think there are any technica l barriers that would prevent other gas suppliers from offering the same weighing services.

Air Products Summary The following information was provided by e-mail: Gas cylinders at Air Products manufacturing and transf ill facilities are weighed with scales to determine the product volume prior to shipment. While Air Pr oducts does measure the weight of residual gas returned for product tracking purposes, they do not perform this measurement individually for each cylinder, but rather for entire cylinder “batches” (to get a total weight returned). For larger packages (MEGC/ISO containers), individual containers ar e weighed at time of fill and time of return.

While Air Products does not have specific information about their competitors’ individual practices, it is a common and widely recognized practice to weigh and r eport the fill volume of cylinders. Practices for recording and reporting residual quantities are more varied by suppliers.

Air Products does not charge any customer a fee to weigh the cylinders or MEGC/ISO containers to determine the fill volume – nor were they aware of any competitor doing so.

Air Products does not individually record residual qu antities (i.e. heels) returned in cylinders, and therefore, cannot (and do not) report this information to customers. They do currently track and record residual quantities in MEGC/ISO containers – while cust omers do not currently request this information, it

is available.

Air Products uses scales with accuracies of < ± 1 % of weight as specified by manufacturer. The scales are calibrated every 6 months and a documented calibration/maintenance procedure is recorded in SAP.

3M The following information was provided by e-mail:

2 ICF left messages with a representative at Honeywell twice in effort to obtain their input but did not ultimately make

a connection.

June 28, 2010 2When providing F-Gases to semico nductor manufacturing facilities (or other electronics manufacturing facilities), 3M does measure with scales the quantity of gas supplied in all cylinders but typically does not weigh returned cylinders with heels. They will wei gh returns that are destined for re-entrance to the process stream as well as returns to be scrapped.

When explained that electronics manu facturing facilities would keep a re cord of all gas received from and returned to suppliers and asked if this informatio n is always communicated to the customers, the response provided was, “I am not sure who the “customer” is in this question. In general, it is felt that if we would need to take an action in support of a customer ’s compliance, we would likely have a fee for that activity.”

Their current scales do have an accuracy and precision of one percent of full scale or better. They calibrate annually at a minimum and in some cases, monthly.

II. Public Comment

Additional insight into this issue was provided via public comment on the proposed F-GHG rule. Select examples of commenters that pr ovided such comments include:

- SF 6 Task Force of NEMA (including Airgas an d US Electrical Equipment Manufacturers)

- Matheson TriGas (EPA- HQ-OAR-2009 -0927-0107)

- Intel (EPA-HQ-O AR-2009- 0927-0089)

SF 6 Task Force of NEMA (including Airgas and US Electrical Equipment Manufacturers) It can be inferred that “The Agency proposes to meas ure residual gas amounts to within one percent:

“If the gas supplier weighs the new or residual ga s, obtain from the gas supplier a detailed monthly accounting, within 1 percent, of new or residual gas amounts in the cylinders returned to the gas supplier.”

NEMA is concerned that this level of a ccuracy will be unattainable in practice. SF 6 gas is commonly shipped cylinders which have a nominal tare weight of 119 pounds. These cylinders are usually filled with 115 pounds of gas. Users typically draw down the gas to about 10-14 pounds before returning the cylinder. The scales currently in use for revenue and accounting have an accuracy of ±2 pounds. If a gas cylinder is returned with 10 pounds of residual ga s, the measurement would result in a potential gas weight error of 20 percent. Conversely, a 1 percent me asurement of “new or residual gas amounts” would require a scale with an accuracy of ±0.1 pounds, or 200 times more precise than currently in use. While the proposed rule allows “best available” measurement accuracies in the 2011 reporting year, NEMA does not believe that 1 percent accuracy will be attainable by 2012. NEMA recommends that the EPA require accuracy no stricter than 10 percent for residual gas amounts.”

Matheson TriGas “Specifically, we believe that MTG can provide a cost effective and efficient solution related to monitoring and measurement of gas “heel” in cylinders. In 40 CFR 98.94 (b) 1 – 6, USEPA proposes methods for measuring and monitoring the gas that remains in a cylinder after a company has discontinued its use. This is an important factor for quantifying the amount of gas that entered the process. 40 CFR 98.94(j) requires that the measurement devices used for this m onitoring must have “an accuracy and precision of 1 percent of full scale or better.”

It is our understanding that many electronics manufacture rs that will be subject to this regulation do not currently have the ability to measure gas heels to this le vel of precision. Many companies will struggle to install expensive flow meters in the shor t timeframe allowed by this proposed rule.

MTG has a readily implementable an d less expensive technology that will meet the USEPA's requirement for accuracy and precision of 1 per cent for heel measurement of the cylinder/container. MTG employs a

June 28, 2010 3cost effective and integrated pressure sensing technology to monitor the contents contained in cylinder tanks. The EPA measurement criteria for accuracy and precision of 1 percent can be achieved through application and combined utilization of pressure transducing and "active" Radi o Frequency Identification (RFID) technologies to monitor the live contents of t he gas products filled in typical cylinder tanks. This integrated technology both measures and records the c ontents and usage of the materials extracted from the cylinder tanks on a continuous real time basis; the measurement is made under both dynamic (extracted use of gas from cylinder tanks) and static (no gas extracted from the cylinder tanks) operating conditions. The usage data associated with monito ring the live contents with in each and every cylinder tank is captured within a dedicated operating sy stem where all data resides for display and record purposes. Historical data logging of gas usage with in predetermined time ranges can be recorded for graphical analysis and interpretation for review as necessary.

The precision and accuracy of our system is 1 percent of full scale or better.”

Intel Development of Heel Factors “Intel is concerned that the proced ures proposed for quantifying cylinder “h eels” (e.g. the residual material remaining when the cylinder is taken off line) may not be realistic. The procedure would require that a set cylinder change out point be set based on either a scale mass reading or a pressure transducer reading. This set point would have to be controlled within 1% to ensure that the amount of remaining material was consistent across every change and could therefore be accurately quantified. While we understand the need to quantify this material accurately, we don’t belie ve the 1% requirement is achievable or necessary. Some of the cylinders containing covered materials may hold as little as ten pounds of material when full. The amount of material remaining when the cylinder is changed may be as little as one pound or less. Therefore, this would require ensuring that the resi dual mass may vary by no more than .01 lbs each time the cylinder is changed. Not only is such a small quantity insignificant in terms of total emissions, but it is doubtful equipment can be found that can consistently measure to this level. Many existing gas cabinet scales are maintained to an accuracy of 1% or even be tter at full scale. However, this same accuracy as a percent of mass will not be achieved when the cylinder is consumed all the way down to the residual heel and only a fraction of the initial mass remains. Some very large containers are actually weighed with truck scales, which usually have increments of 10 or 20 lbs. The sa me point is true when cylinders are monitored by pressure instead of mass. Commonly used pressure transducers are accurate to 1% of full scale, or sometimes better. Again, this percent accuracy will not be achieved when only a fraction of the full scale mass remains and it will not be possible to manage residual heels within 1% consistently. Intel suggests that a more reasonable requirement is that cylinder changes be maintained within a limit of +/- 10%, or +/- 5 lbs. mass, whichever is higher.”

III. Summary of Information Available To-Date

The responses above provide a good indication of the practices currently in place within industry.

- Gas suppliers already meet many of the accu racy and precision requirements stated in the proposed subparts. However, this is not always the case, especially when there are relatively small quantities of gas being measured.

- The practice of weighing residual gas in cylinders is varied from gas supplier to gas supplier. This practice may be currently available for indivi dual cylinders (for a fee and per request of a customer), in bulk for batches of cylinders, i ndividually for MEGC/ISO containers, or when the returns are to be reprocessed and recycled.

It should be noted that:

- Some electronics manufacturing facilities (speci fically, semiconductor manufacturing facilities) have claimed that they do not currently meet t he proposed accuracy and precision requirements

and would have to either incur the cost of obtaini ng scales that do meet the requirements or incur the cost of services provided by gas suppliers who have scales that are one percent accurate.

June 28, 2010 4June 28, 2010 5 - In the current monitoring and QA/QC requirements for subpart DD, electric power systems are already required to weigh their beginning and end of year storage inventory using scales with the same precision and accuracy requirements as the scales used to weigh gas that is returned to suppliers. Therefore, electric power systems are not dependent on gas suppliers to perform the function of weighing gas that is returned to suppliers. However, since the gas suppliers are already performing the role of collecting used cy linders from the utility and recovering gas from the cylinders, it could very well be more cost-e ffective for electric power systems to pay gas suppliers to weigh returned gas than weighing the gas themselves. Gas suppliers would then need to ensure that they change their practices in order to meet the reporting requirements.

- The electrical equipment manufacturers submitted their comments through the SF 6 Task Force of

NEMA. Their comments indicate that scales curren tly in use in their industry have an accuracy of ±2 pounds, which will not meet the proposed accuracy and precision requirements.