Studies fill holes in emissions data.

As foundries prepare to comply with updated regulations, they must first concentrate on the search for updated information.

"Since 1980, one of every four foundries has shut down due to noncompetitive processes and environmental regulations," pointed out Jerry Rogers, General Motors, "yet foundries are vital to the Dept. of Defense and the automotive industry, as well as being the sixth largest industry in America."

Emissions control is one of the major challenges facing foundries today. With the 1990 Clean Air Act Amendments (CAAA) and Maximum Achievable Control Technologies (MACT) standards scheduled to take effect in 2000, the industry has had to speed up the pace of its emissions control. Foundries have had a hard time with this subject though, mainly because the industry has never done a complete inventory of all its pollutants.

"The biggest problem for foundries now is that emissions data is scarce and the little data that is available is 10-30 years old," said Gary Mosher, director environmental affairs, AFS. "This information doesn't reflect current processes and therefore foundries are looking at a big black hole where the information should be."

At the 7th AFS Environmental Affairs Conference, June 11-13 in Arlington Heights, Illinois, 188 metalcasters gathered to try and fill in some of that information, as well as to learn about a variety of other environmental and safety issues.

Two studies discussed at the conference focused on arming foundrymen with the emissions data so necessary to CAAA compliance. In the short term, these studies should assist foundries in filling out their Title V permits, but more importantly, these projects will fill the information gap and boost metalcasters' awareness level and knowledge.

Benzene and Formaldehyde

Under Wisconsin administrative codes (and subsequently Title III of the CAAA), both benzene and formaldehyde are classified as air toxics. In mid-1989, Wisconsin foundries were required by the state Dept. of Natural Resources (WDNR) to estimate their emissions of any of the 437 compounds classified as hazardous air pollutants (HAPs).

"Most foundries complied but, with the exception of carbon monoxide, they did not have a lot of experience with gaseous emissions," said Jim Rickun, RMT, Inc. "As a result, many foundries reported no benzene emissions, relying on Material Safety Data Sheets. But benzene is formed as a by-product of foundry operations.

"After it was announced that MACT would take effect in 2000, WDNR, in June of 1994, ordered foundries to do specific process testing for benzene and formaldehyde."

To eliminate confusion, RMT, Inc., Madison, Wisconsin, was retained by the Wisconsin Cast Metals Assn. (WCMA) and AFS to conduct source testing at ferrous foundries on processes that may emit benzene and formaldehyde. These processes include pouring, mold cooling and casting shakeout operations.

Rather than have every foundry in Wisconsin conduct these costly tests, the WCMA worked with the WDNR to conduct a group testing effort. The purpose of the group effort was to test a subset of similar foundry processes and obtain benzene and formaldehyde emission rates that may be representative of the members of the group.

The Testing Process - Participating foundries were grouped by mold sand type: green sand, nobake and shell. Five facilities were tested from the green sand group, two from the nobake group, and one from the shell mold group.

Since pouring operations vary from foundry to foundry, for this project, if the pouring station/location was equipped with local ventilation, direct testing was conducted.

Table 1. Results of WCMA Benzene and Formaldehyde Emissions Study
from Green Sand/Nobake Foundries Compared to Previously Available
Data through EPA(*)

                          Formaldehyde              Benzene

                        WCMA      Previous      WCMA      Previous

pouring              0.00315      -           0.0059      -
cooling              0.0020       -           0.0338      -
pouring & cooling    0.00515      0.00098     0.0397      0.049
shakeout             0.0022       0.0084      0.0058      0.4164
total                0.00735      0.0084      0.0456      0.4654

Foundries cool molds in a variety of ways. Molds can be conveyed automatically through cooling tunnels or are placed on an open floor space to cool. Again, in ventilated areas direct testing was conducted. If several ventilation points were used, a representative point was selected.

Because of the particulate emissions generated by the shakeout operation, almost all shakeout points are ventilated. The most common tested shakeout method used a rotation drum to remove sand from the casting.

The group prepared a generic stack test protocol to be submitted for review by the WDNR. The protocol included descriptions of the sampling equipment and test methods, as well as the process to be tested, a description of the operating variables and a description and number of sampling ports, locations and distributions to be tested.

Results - The findings of this study were based on a limited number of tests and compared to prior EPA VOC emissions and data from Scott and Bates' work, done in 1980 at the Univ. of Alabama-Birmingham. However, the results do indicate that benzene and formaldehyde emissions from green sand/nobake foundries are actually lower than what was previously known (Table 1).

"Money was not set aside in this study for statistical analyses of the results," said Rickun, "rather, the WDNR requested the in formation to characterize a specific operation in the foundry so that another foundry that was not part of the direct testing could attempt to find a process with similar characteristics of its own. That foundry could then feel confident using the emission information from the tested foundry and apply the information to their own foundry operations."

It is important to note that Wisconsin's regulations set benzene and formaldehyde limits much lower than federal standards, and the results if this study are in compliance with the state's limits. Therefore, foundries in other states can use this information as a resource to estimate their own emissions of the substances to determine if they are within the federal limits.

Published results of this study will be available this fall from AFS.

Foundry of the Future

Another important project designed to help foundries find more cost-effective and practical ways to comply with environmental regulations is the Foundry of the Future Project. The project, sponsored by CERP (Casting Emission Reduction Program), is designed to improve and/or develop materials and processes in foundry technologies to allow the U.S. casting industry to be competitive while working to achieve a zero effect on the environment.

"That is a pretty lofty goal," said Rogers, "but hopefully we can meet it."

CERP is a national program using a cooperative government/industry approach to solve foundry environmental issues. It is a five-year, $50 million congressionally appropriated dual-use program funded through the Advance Research Project Agency (ARPA) to McClellan Air Force Base, Sacramento, California, and from funding included in the FY94 and FY95 Defense Bills.

"The motivation behind this project is CAAA, which may force foundries to close or move offshore by 2000 due to the high cost of regulatory compliance," said Rogers. Other CAAA requirements - including that foundries be subject to MACT by 2000, and the increasing number of substances classified as HAPs - have led to the building of a pilot foundry at McClellan Air Force Base to study foundry air emissions.

According to Rogers, the foundry will model metalcasting emissions; develop new instrumentation for emission measurement with American Industry and Government Emissions Research (AIGER); conduct national source testing; develop emissions baselines and alternative materials, chemistries, and processes; and evaluate cast product attributes.

The pilot foundry will use green sand molding to produce cast iron four-cylinder engine blocks as a test part. The engine blocks will be cast at a rate of 50 per hour for two hours. The foundry will also have aluminum and ductile iron capability and full process control and source monitoring.

CERP's initiative includes the characterization, validation and analysis of existing foundry emissions data; the identification of data "gaps" and collection of that data at foundries; correlation of HAPs to sources; construction of an emissions database; and the ranking and prioritizing of emissions sources for process modification.

"There just isn't a lot of data out there and we plan to identify the gaps," said Rogers. "We also are conducting a field program in which we will visit 22 foundries around the country." Field testing was expected to begin in July at Saginaw Metal Casting Operations, Saginaw, Michigan.

The processes to be tested include melting, post metal treatment, metal transfer, pouring, cooling, shakeout, cleaning and finishing, sand preparation, mold making, mold coating, core-making/coating/drying, core storage and material storage and handling.

As a result of the studies at the pilot facility and in the field, CERP will provide a resource for evaluating new material sand processes to solve emission-related problems in a production-like setting. They will minimize manufacturing risk and reduce lead time for new materials, processes and procedures and the pilot facility will have full instrumentation and nondestructive evaluation capabilities for determining cause and effect relationships.

"That's important because often times you find resistance in the manufacturing facilities to new processes," said Rogers. "We've got a full production facility where we can check out everything before it is adopted by an existing plant."

In 1993, McClellan AFB was on the list of base closures as a result of defense expenditure cuts. Equipped with one of the country's most advanced metal materials manufacturing and testing facilities, McClellan was able to work with the private sector to delay its closing. The CERP project will be completed before McClellan faces closure again.

RELATED ARTICLE: Foundrymen Talk Compliance

As representatives from foundries around the U.S. gathered at the AFS Environmental Conference, it was clear that some concerns cut across regional and process differences.

Title V air emissions permitting, was on the minds of many. "It's the next big question," said Richard Hodge, East Jordan Iron Works, Inc., East Jordan, Michigan. Like many, his foundry needs outside help to work through the myriad requirements of the permit. "We're taking bids for consulting work right now," he said. "We want to give ourselves as much time and help as we can."

Many firms have already taken steps toward Title V compliance. "We have a baghouse already but there are still a lot of fugitives," said Paul Saarni, Thunder Bay Manufacturing Corp., Alpena, Michigan. "The cost of the permit is also a concern."

As regulatory reform surfaces on the congressional agenda in Washington, and OSHA and EPA begin to talk about a less punitive approach to enforcement, many foundries have enjoyed a less adversarial relationship with state and federal regulators in the past few years. Many shops haven't had a visit from various agencies in years, or have been working with them on compliance. Kenneth Kephart, Stahl Specialty Co., Kingsville, Missouri, said, "We are on pretty good speaking terms with the agencies; we exchange questions and information. Most of the agents are pretty reasonable."

Hodge added: "We have a good relationship with the Michigan DNR, because we're very environmentally proactive. We're concerned about it ourselves."

"What's driving compliance is not fear of the agencies," said Scott Vandenbos, Deere & Co., Waterloo, Iowa. "It's health care and liability costs."

Gary Mosher of AFS concurs: "The technology is headed toward zero emissions and green foundries," he said. "And the industry will do it on its own because it knows it's in its own best interest. But the agencies haven't been able to resist getting involved and regulating what is evolving naturally toward what they want anyway."

That technology comes from industry suppliers, who can do much to ensure that what goes into a foundry is as safe as possible. "Suppliers have helped us," Saarni said. "For instance, they encouraged us to change some of our coatings from isopropyl based to water based. They also worked with us on some health issues."

Local communities also tend to drive the progress toward environmental improvement in foundries. "We get pressure from the community all the time about odor or dust," Vandenbos said. "But I think it's a good check and balance."