by Nick Bennett, NRCM staff scientist
Dear Chairman Scott and Members of the Board:
My name is Nick Bennett and I reside in Hallowell. I am the staff scientist for the Natural Resources Council of Maine, and I am testifying on the Dragon Products applications for closure and reclamation of its cement kiln dust (CKD) and waste clinker piles.
Dragon’s Thomaston operation, as the Board knows, is a very large industrial operation, which has historically produced CKD and waste clinker as byproducts to cement manufacturing. These byproducts accumulated into very large piles of caustic material that Dragon has stored uncapped and unlicensed for over a decade.
These piles pose a threat to the surrounding environment, which is obvious from photographs of waste leaching into surrounding water (see attached photos). It is unacceptable that DEP has not acted to require remediation of contamination and compliance with state solid waste regulations more quickly.
As the Board considers its next steps, it should keep in mind that the critical goal of its actions must be to stop off-site migration of waste from the two piles, whether through surface water, ground water, or air. There may be many different strategies to accomplish this, but the off-site migration of contaminants needs to stop. There are a number of deficiencies in Dragon’s applications that raise questions about whether the proposed actions will stop contamination from leaving the site. The following will discuss these deficiencies.
The nature of the materials, the activities in question, and the very high level of concern about dust from the piles among residents in the surrounding areas make this deficiency striking. CKD comes from the filters in the pollution control devices for the plant. In other words, this is originally very fine, mobile particulate matter that goes up the smokestack. Although we understand that waste cement products may interact with water and their particle size may change over time, we also understand that there is a fair amount of fine material remaining in the CKD pile. In addition, USEPA notes in its study of CKD that:
In an effort to keep the dust down, many facilities add water to CKD prior to disposal to form larger clumps or nodules. In addition, as CKD sits in a pile exposed to the elements, occasional wetting by rainfall results in the formation of a thin surface crust in inactive areas of the pile. However, based on field observations during the site sampling trips, neither the formation of nodules nor the natural surface crusting eliminates the potential for CKD to blow into the air. Nodulizing the dust prior to disposal provides incomplete and temporary control because the entire dust volume is not nodulized and because the dust eventually dries and returns to a fine particulate that is available for suspension and transport. Likewise, a surface crust may develop, but (1) the crust breaks when vehicles or people move on the pile…
Therefore, when bulldozers and other large equipment are used to move the waste from the pile, dust emissions are inevitable. Similarly, for the clinker pile, the proposed reclamation process involves the crushing and screening (presumably by shaking material through a progressively smaller series of screens) of rocky materials. This again is clearly an activity that is bound to generate large amounts of dust.
Dragon states in its applications that it will “monitor” dust emissions and cease operations if a 10% opacity “standard” is exceeded, but it does not describe either the basis for this standard or how it will monitor. Nor does it describe how long the standard would have to be exceeded to stop operations, where it will measure emissions, or, perhaps most importantly, what precautionary measures it will take to reduce the production of dust.
Finally, CKD is not just ordinary dust; it is highly alkaline and contains many other contaminants . The alkaline nature alone greatly increases its potential to be an irritant and to cause damage to the environment.
I recommend that the Board require a detailed dust monitoring and control plan as part of any action it takes on these applications. Again, it is critical to prevent off-site migration of dust from the waste piles. The Board should also require Dragon to sample surrounding areas and residences for accumulation of dust from the piles, as part of a comprehensive off-site monitoring plan (discussed further below), and to remediate any dust accumulations or damage the dust has caused.
2. The plans as written are unlikely to prevent continued migration of leachate from the site.
Leachate is the contaminated liquid produced when ground water, surface water, or rain comes into contact with the waste materials in the CKD and waste clinker piles. In its application concerning the CKD pile, Dragon states that:
Leachate in the form of precipitation falling on the reclaim area will be captured in the active reclamation area…Water collected in the reclamation area will infiltrate the CKD pile or evaporate .
This is unacceptable. Leachate that is absorbed into the pile does not simply disappear – it will leach out from under the pile, as the attached aerial photos have shown has already occurred. As DEP noted in a September 8, 2006 memo on the waste clinker pile, all leachate should be stored only in lined ponds or in leachate tanks and “any runoff from an open face of waste clinker should be collected, contained and treated as leachate” . This is a reasonable recommendation, and DEP made it to prevent leachate from escaping from the waste clinker pile. Therefore, I remain puzzled why DEP has not made a similar recommendation regarding the CKD pile. Shouldn’t any runoff from an open face of the CKD pile be collected and stored as leachate as well? The implication is that DEP finds Dragon’s proposal simply to allow leachate to continue to infiltrate the pile acceptable, which is not justifiable. The Board should ask the Department to explain this.
There may be a number of strategies to prevent leachate from the CKD pile from continuing to migrate off the site, such as pumping leachate out of the CKD pile and the quarry it is in so that leachate remains below the level of the surrounding groundwater. However, Dragon’s proposal simply to let leachate seep into the uncovered part of the pile will not stop migration of leachate off-site, and DEP’s apparent failure to recommend another strategy is concerning.
Therefore, we recommend that the Board require DEP and Dragon to adopt management plans for the CKD and waste clinker piles that prevent further leachate from escaping the site and resolve the apparent discrepancies in DEP’s leachate management recommendations for the clinker and CKD piles.
3. The applications lack specific leachate and minimization and management plans for winter months.
It is unclear from Dragon’s application what it intends to do about leachate from the CKD and clinker piles during winter months. Dragon states that it will only be pursuing reclamation activities during months where freezing does not occur, but winters along the Maine coast often have frequent thaws and rain events. Does Dragon propose to leave its reclamation areas, which encompass several acres on both piles, exposed during this time? We found no mention of plans to cover the areas of active reclamation prior to ceasing activities during winter months. Certainly there will be no time for plants to grow between the end of construction operations in the fall and the onset of winter. Therefore, some sort of liner to cover the unvegetated surface of the piles would likely be helpful during the winter months to keep rain and snow off the piles. It is important to note that any snow that accumulates on the piles will melt in the spring and leach out from under the piles. There may also be other strategies, such as pumping throughout the winter months, that will solve this problem, but a would certainly help minimize leachate generation.
We recommend that the Board require Dragon to specify how it plans to control leachate during winter months.
4. The proposed soil and vegetation cover for the inactive areas of the piles may allow water to percolate through and may not comply with state solid waste regulations.
Although Dragon’s proposal to provide a temporary soil and vegetation cover for the areas of the two piles where it is not carrying out construction activities may reduce the amount of water eventually contacting waste, it is unlikely to eliminate it. Water moves through soil, even vegetated soil. In addition, as the Town of Thomaston noted in its prefiled testimony, the proposal to use 12” of soil appears to violate DEP regulations which require 18” of soil or a geosynthetic cover material with a minimum thickness of 20 mils .
The Board should require the applicant to study the feasibility of lining even the parts of the pile that are covered with temporary vegetation (a plastic liner could be placed underneath the soil cover), because a soil and vegetation cover alone will not prevent rain from percolating into the CKD and waste clinker and creating leachate. It should also require the applicant to comply with relevant DEP regulations as noted by the Town of Thomaston.
5. The applications lack a comprehensive environmental monitoring plan.
Without such a plan, Dragon and DEP cannot be sure that contaminants stop leaving the site. In addition, a plan is needed to document the extent of off site contamination that has already occurred, and to provide the data necessary to perform any necessary off-site. We understand that DEP has recently recommended a comprehensive review of the CKD and clinker pile environmental monitoring programs7. We support that recommendation, and wish to emphasize that such a program must be comprehensive, so that Dragon can ensure that contamination stops leaving the piles in any medium. The plan should also include protocols for reporting any escape of contaminants to DEP and the public and rapid response in the event that further contamination does leave the site. In addition, any existing off-site contamination via ground water, surface water, and dust from the piles must be documented and cleaned up, and any impacts to the environment or public health, if noted, may require additional action.
It is good that DEP is finally moving to get these sites cleaned up, and the reuse of the waste material is an appealing way to do this. However, since this process will take many years, even decades, to accomplish, remedial action that stops the migration of contaminants from the sites is necessary, and this needs to happen now. These plans as written are not likely to accomplish this.
Therefore, I recommend that the Board require, as part of any action it takes on these applications:
Thank you for the opportunity to testify, and I would be happy to answer any questions.
Photo of cement kiln pile at Dragon Products in Thomaston
Photo of waste clinker pile at Dragon Products in Thomaston
