D l t f BMP f R kDevelopment of BMPs for Rock Blasting Activities to Protect Water gResources

Brandon Kernen, PGNH Department of Environmental ServicesBrandon.Kernen@des.nh.gov (603)271-0660g ( )

Primary Objectives of this InitiativePrimary Objectives of this Initiative• Prevent contamination and dewatering of

t l llwater supply wells• Establish a process to monitor for

impacts• Establish a process to mitigate confirmed p g

impacts• Identify legal approaches and • Identify legal approaches and

requirements associated with protecting water resources and public healthwater resources and public health

Why?Why?1) R f th l f it t / it it d1) Re-occurrence of the release of nitrates/nitrites and

organic compounds to groundwater and surface water above allowable standards.

2) Significant health threat to the public associated with drinking water contamination.drinking water contamination.

3) Lack of planning or knowledge to:Prevent contaminationPrevent contaminationMonitor drinking water suppliesAddress impacts to water resources

4) Level the “playing field” between industry experts4) Level the playing field between industry experts, alleged experts, municipalities and homeowners.

Blasting in NHBlasting in NH Blasting is performed to break rock to:

–Quarry and process aggregate material–Excavate a right of way for roads/utilities–Construct surface structures such as of

swimming pools or foundations–Alter the terrain to allow for site

development

Blasting is accomplished by discharging an explosive confined in a boreholep

Blasting DesignBoreholes are drilled into bedrock and filled with Boreholes are drilled into bedrock and filled with explosives

Water Contamination Opportunities Associated with Blasting ActivitiesAssociated with Blasting Activities

1) Storage and handling of explosives2) Method used to fill blast holes with explosive

materials3) L f l i i bl t h l f t3) Loss of explosives in blast hole fractures4) Incomplete combustion of explosive material5) Cleaning of eq ipment 5) Cleaning of equipment 6) Residual explosive material on faces of

blasted rock/stormwater run-offblasted rock/stormwater run off7) Potential for secondary chemical reactions

associated with exposing new rock faces or p gintroduction of chemicals/nutrients into the subsurface

Rock Removal and Blasting Productsg• Approximately ½ lb blasting product is

used per ton (.45 yd3) of rock excavated.p ( y )

• Percent nitrate by weight for one typical bl ti d t 62% blasting product = 62%

• Large commercial and highway projects in • Large commercial and highway projects in NH have excavated 100K-700K yd3 of rock(110,000-770,000 lbs of nitrate associated

ith l i )with explosives)

Importance of Groundwater in NHp

•• Approximately 230 000 drinking water Approximately 230 000 drinking water •• Approximately 230,000 drinking water Approximately 230,000 drinking water supply wells exist in New Hampshiresupply wells exist in New Hampshire

•• 36%36%--44% of the population rely on their 44% of the population rely on their i t t l ll i t t l llown private water supply wellown private water supply well

•• 60% of the population relies on 60% of the population relies on groundwatergroundwatergg

Location of Drinking Water Drinking Water Supply Wells in New HampshireNew Hampshire

Why Rock Blasting Impacts May Become CMore Common in NH

• In densely populated areas only land • In densely populated areas only land that requires significant alteration is available for development available for development.

Ad i bil k hi • Advances in mobile rock crushing technology make land alteration

f iblmore feasible

http://www.rocksystems.com/machinery/crushing-equipment/jaw-crushers/R2304

Wells Impacted by Blasting in NHWells Impacted by Blasting in NH• Generally within 2000 feet of blasting site

• Contamination levels exceeded drinking • Contamination levels exceeded drinking water standards for 2-18 months

• Contaminants detected above MCL• Nitrate• Nitrite• Benzene

Stormwater from Quarry

Regulation of Rock Blasting/Water Resource Protection in NHesou ce otect o

• Municipal Excavation Regulations (can address local safety concerns)address local safety concerns)

• Municipal By-laws and Site Plan Review Regulations (protect public health)

• NH Alteration of Terrain Regulations• NH Alteration of Terrain Regulations

• NH Waste Site Remediation Regulations

• State/Federal UIC RegulationsMunicipalities have the most extensive legal Municipalities have the most extensive legal authorities and often more regulatory access

to blasting projects.

NH Groundwater Quality StandardsNH Groundwater Quality Standards

Cannot be exceeded except for Cannot be exceeded except for designated areas associated with:

• Permitted wastewater disposal systems

• Permitted groundwater discharges

St t l d t b d d t State law may need to be amended to allow for water quality degradation

i t d ith bl tiassociated with blasting.

July 2009 Revised Blasting/Water Resource Protection DocumentResource Protection Document

1) Narrative characterizing:• Background• Potential impacts to water resources (quality

and quantity)and quantity)• Potential BMPs• Legal authority to regulate blasting relative • Legal authority to regulate blasting relative

to water resource impacts2) Attachment A – suggested language to include 2) Attachment A suggested language to include

in site plan, excavation and blasting regulations3) Attachment B – suggested water resource

monitoring and mitigation program components

BMPs• Explosives Selection• Drilling PracticesDrilling Practices• Material Handling Practices• Blast Hole Loading Practices• Blast Hole Loading Practices• Blasting Performance• Fragmented Rock Storage Handling • Fragmented Rock Storage, Handling,

Processing and Use• Management of Surface Water Run-off• Management of Surface Water Run off• Spill Prevention Measures and Spill Mitigation

PlanPlan• Water Quality and Water Level Monitoring

Future Initiatives• Revise document respond to public • Revise document, respond to public

comments R i d fi li d t• Revise and finalize document

• Collect data if willing partners can be identified

• Sample drinking water wells near blast p gsites

• Amend Alteration of Terrain Regulations Amend Alteration of Terrain Regulations to include provisions for blasting/water resource protectionresource protection