Editor’s note: This is the third in a three-part series by Portola resident Valari Simison, whose residence is 60 feet south and 200 feet west of the mine property under consideration for expansion.
The previous two “Letter to the Editor ” articles outlined how the proposed North Portola sand/aggregate mine located in a residential neighborhood would endanger the health and well-being of local citizens by desecrating and polluting the environment. After discussing aquifer depletion and water contamination along with air quality degradation in the Part 1 article, Part 2 covered concerns regarding noise and light pollution. This final installment will address the hazards and harmful effects of air & ground vibrations, erosion, wildfire potential, and community safety.
Air and ground vibrations
The mine permit mentions several sources of potential vibrations: blasting, multiple earth-moving equipment working in unison, and truck transport. Underestimating the issue of vibrations can lead to unexpected damage to homes surrounding the mine complex along with health concern complaints. Noise and vibrations are often linked closely together due their nature; however, more and more studies are coming forward labeling “vibration annoyance” as a separate entity. These studies are showing that exposure to continued and elevated levels of vibrations have an adverse effect on human well-being.
The human body’s perception of vibrations is a complex phenomenon. There is no specific organ that senses vibration. Rather it is a set of sensors that determine deformation and relative displacement of organs and tissue at certain wavelength frequencies. It involves a combination of the vestibular system (the inner ear), the somesthetic system (skin and specialized corpuscles located in muscles and tendons), the auditory system (ear and auditory processing mechanisms), and the visual system (eye and visual processing systems). It is a whole body event. The effects of elevated levels of vibrations are similar to noise—anger, disappointment, withdrawal, helplessness, depression, anxiety, distraction, and agitation. Vibration annoyance is clearly influenced by noise, increasing with elevated noise levels.
Airborne vibrations originate with earthquakes, volcanic eruptions, and industrial blasting. Blasting generates air blast (air overpressure), ground vibrations, fly rock, “fines”, fumes, and dust. Blasting affects neighbors, animals, structures, utilities, and the environment. Air overpressure that reaches 125 dB creates vibrations that damage walls, rattles loose items, and breaks windows. Ground deformation leads to cracks and slides. Such blasting has the potential to affect local fault lines increasing the area exposure to earthquakes. Industrial blasting must be done by certified blasters.
Ground-borne vibrations emanate from earth-moving equipment and truck transport through the ground to adjacent buildings through surface waves. Unlike in air, there are several types of wave motions in solids including compression; shear, torsional, and bending. Vibrations can be a single pulse, a series of pulses, or continuous oscillatory motion. The HCC permit requesting 700 daily round trips on Meadow Way would result in heavily loaded dump trucks every 2 minutes for 12 hours or every 4 minutes for 24 hours. While these loaded trucks are traveling away from the pit, emptied trucks would be returning to the pit. This would go beyond vibration annoyance becoming a vibration hazard. This health and safety hazard would affect the well-being of community members who have supported this community.
With the amount of excavation and water usage that this mine proposal is requesting,erosion becomes another predominant concern. The mine permit requests excavation that will leave 410’ cliffs at a 63 degree slope. A 63-degree slope is so steep that standing on top of the 410’ cliff, it would look to be a straight-down, vertical drop. Creating these precipitous walls will be done in coordination with the use of 50,000 gallons of water daily for processing materials.
This excavation will erode this mountainside by tearing down its infrastructure, leaving it vulnerable to the effects of the weather—primarily water in the form of precipitation or snow melt.
The excavation and water usage from processing operations will create loose sediment. The sediment pond is a way addressing this side effect of mining. However, high precipitation from heavy rains or high snow melt are a two-fold danger to the environment created by this pit mine. First, these natural weather events can create extensive runoff that will load nearby bodies by washing loose sediment into those bodies of water. Second, the proposed sediment pond may not be able to contain this extensive runoff.
Consequently, the sediment pond contents are released further degrading surrounding creeks, streams, rivers, and wetlands. Given that this 450’ toxic-filled sediment pond is directly above several homes, those locations are endangered by possible dam breakage. There have been dozens of dam breakages during recent history. These situations have some of the worst environmental consequences of all industrial incidents: compromised drinking water, property damage, health risks, and polluted aquatic tributaries.
Another reason to not place this industrial mine complex in a residential neighborhood or adjacent to the Middle Fork of the Feather River with its Wild and Scenic designation.
This industrial complex mine will have a fleet of heavy-earth moving equipment, factories with multiple moving parts, and high levels of storage for diesel, hydraulic fluid, and transmission fluid. A spark from any of these sources or an industrial accident could set off a wildfire that would erase Portola and probably further structures and vegetation from the map. We have the fires from the past few summers as evidence to these possibilities.
There are a number of issues that will physically endanger our local environment if this industrial mine complex is allowed to commence. At present, there are over 20 open test holes exposed on this property at least 130’ deep.
These open test holes pose a safety issue to wildlife, community members allowed to transverse on this property, and the purity of the aquifer. Thus local wells may be already contaminated from these open accesses to the aquifer.
Excavation from this industrial mine will create 410’ cliffs. Industrial machines will be stored at the site along with the accompanying factories All of these scenarios will pose threats to curious adventurers. Fencing will not be adequate to protect these individuals.
The requested 700 round trips by dump trucks for transport will generate a tremendous burden on the Meadow Way roadway for local citizens. There will be a backlog of trucks coming onto and leaving Meadow Way. This situation is primed for an accident, even a fatal accident, by overburdening this rural, country byway. A traffic study must be employed to research the feasibility of this ludicrous idea.
The HCC’s permit application offers plans to mitigate the mine’s destructive effects on the environment and its residential members. Unfortunately these mitigation plans to ameliorate the mine’s effects on each section of the permit are either:
- not feasible,
- inadequate, or
HCC’s permit wording portrays them as a “Profit at All Costs” operator. Their interest is not in assisting our community or protecting its members and the environment. This company is here for the sole purpose of making money. They are not a part of this community. Their mine might offer jobs, but to whom? Will those jobs go to local residents or will the jobs go to employees already attached to HCC from outside of our area? HCC has not portrayed itself as a good neighbor, as evidenced by the 20 + open test holes dotting the hillside behind our homes.
The General Plan for Plumas County reiterates over and over the need to preserve and protect our natural resources. Our natural resources make Plumas County what it is. These natural resources are what draw people here and keep them here. The mental, physical, and emotional health of local constituents is at stake, as described in this paper. Would anyone on the Board of Supervisors or the Planning & Building Department choose to live next to such an industrial complex? As the government officials elected to protect the well-being of their constituents, they must reject this permit by giving a firm “No” to this horrific proposal.
A plea is being made to respect the citizens who have supported the Plumas County through property and sales taxes, businesses, employment, local consumerism, services, and charitable causes. We appeal to the Plumas County Board of Supervisors and the Planning & Building Services to reject the permit for this industrial “aggregate and sand” pit mine with asphalt plant, lime plant, a rock crushing plant, on-site diesel storage for 10,000 gallons of fuel, 55 gallon-drums of hydraulic and transmission fluids, and sediment pond (450’) for particulates and potential toxins on APNs 025-050-055 & 025-100-036.
Plumas County Resident–42 years