10.d 1 Review of 2017 Annual Operating Permit for the Tiller Scandia Mine
Memorandum
To: Scandia City Council Reference: Tiller Corporation— 2017 Annual
Operating Permit Application for
Scandia Mine
Copies To: Neil Soltis, City
Administrator
Mike Caron, Tiller
Corporation
Christina Morrison, Tiller
Corporation
Kirsten Pauley, Sunde
Engineering
Project No.: 16322.003
From: Sherri Buss, RLA AICP,
Planner
Routing:
Date: February 8, 2017
SUBJECT: Tiller Corporation, Inc. – 2017 Annual Operating Permit (AOP)
Application for a Mining and Processing Operation
MEETING DATE: February 21, 2017
LOCATION: Sections 7 and 8, Township 32 North, Range 20 West;
all that part of the south half of the Northwest Quarter of Section
35,Township 32, Range 20, Washington County, Minnesota; and
Section 17, Township 32, Range 20
APPLICANT: Tiller Corporation
P.O. Box 1480
Maple Grove, Minnesota 55311
60-DAY PERIOD: March 25, 2017
ZONING: Aggregate Mining Overlay District
ITEMS REVIEWED: Application, Plans and Related Submittals; subconsultant and
agency comments, site visit findings
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 2 February 21, 2017
BRIEF DESCRIPTION OF THE REQUEST:
Tiller Corporation has applied for its 2017 Annual Operating Permit (AOP) for an existing sand
and gravel mining operation located on Manning Avenue near 225th Street in Scandia. The site
has been actively mined since 1966, and currently operates under Conditional Use Permits
(CUP’s) granted by the City on May 20, 2008. The Tiller mine site previously operated under a
CUP issued by Washington County when the County exercised land use authority within New
Scandia Township. Permitted activities included the mining and processing of aggregate, the
production of hot-mix asphalt, and the recycling of concrete and asphalt products.
The City’s Mining Ordinance specifies an AOP cycle that coincides with the active mining
season. Applications are due by January 31 each year, so that permits can be approved before
the start of the mining season in that year.
The applications for the Scandia Mine Site since 2010 have included both the Tiller site and the
adjacent site that was formerly the Dresel Mine site. The former Dresel site is south of the Tiller
mine. Tiller purchased the Dresel site in 2009 and is operating both sites. The City issued a
CUP for mining and processing at the Dresel site on May 20, 2008. As the Owner of both sites,
Tiller needs to comply with the conditions of both the Tiller and Dresel CUP’s. Issues and
compliance with each are discussed in this report.
The City Council approved a CUP and an AOP for Tiller’s Zavoral Mine Site on February 19,
2013. Tiller began operations at the Zavoral Site in the fall of 2013. Tiller and its operators
transported aggregate materials from the Zavoral Site (Class “C” add rock) to the Scandia Mine
site for storage and processing during the 2013-2016 mining seasons. Mining activities at the
Zavoral mine ended in 2016, and therefore transport of material from that mine to the Scandia
mine will not occur in 2017.
EVALUATION OF THE AOP REQUEST
The Applicant is requesting an Annual Operating Permit (AOP) for a mining and processing
operation. The permit requirements are governed by the City’s Ordinance No. 103, Regulation
of Mining and Related Activities, which is Chapter 4 of the Development Code. The Ordinance
requires review of the following items for the AOP:
1. The operating conditions of the previous year and conditions required by the CUP’s for the
Tiller and Dresel sites.
2. Proposed operating conditions and any variation from the previous year.
3. Results of the annual inspection by the City.
CONDITIONAL USE PERMIT REQUIREMENTS
Tiller Mine Site
The City of Scandia approved a Conditional Use Permit for sand and gravel mining and
processing at the Scandia Mine site for Tiller Corporation on May 20, 2008. The conditions
included the items noted on the table below. Tiller’s performance is also indicated on the table
and in the text sections that follow:
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 3 February 21, 2017
2016 issues are identified in underlined text.
Condition Deadline
Specified
in CUP
Status Notes
1. Comply with CUP Ongoing + In process--monitored by City staff and
consultants
2. Comply with
Rules and
Regulations
Ongoing + In process--monitored by City staff and
consultants.
4. Permits from
CMSCWD
None
specified
* Received July 10, 2008 and on file at
the City. CMSCWD Administrator noted
that Tiller needs to renew its Watershed
District permit (5-year renewal) and
submit the required lake monitoring plan
with the permit renewal.
5. Installation of
three Monitoring
Wells
July 20, 2008 + The required monitoring wells were
installed in 2008. One well was taken
out of service in 2011 to accommodate
reclamation activities (MW -2). Tiller has
sealed this well and will revise the
groundwater monitoring plan to reflect
the change. Monitoring results for 2016
were provided with the AOP application
and reviewed by Leggett, Brashears,
and Graham, Inc. (LBG), the City’s
groundwater consultant.
6. Ground Water
Monitoring
July 20, 2008 + Plan was approved in the fall of 2008,
and revised in 2013 The plan is on-file
at the City.
7. Excavation below
water table
May not
begin before
August 20,
2008
+ Excavation into the water table began in
2009. CUP permits mining into ground
water to a depth of 50 feet. Excavation
into the groundwater table occurred in
2013 to a depth of 15 to 20 feet. Tiller
did not mine into the groundwater table
in 2014 or 2015, but did mine
approximately into the groundwater
table in 2016 to about the same
maximum depth as the mining activity in
2013. Excavation into the groundwater
table may occur again in 2017 to a
maximum depth of 20 feet. Water level
data is collected on an ongoing basis
and submitted to the City. Water level
data has been submitted for this
application, and LBG’s review and
recommended conditions for Tiller
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 4 February 21, 2017
Condition Deadline
Specified
in CUP
Status Notes
documentation of excavation depths in
2017 are discussed in the section on
Groundwater Monitoring.
8. Production Well
Records
July 20, 2008 + Production well records are being kept
by Tiller Corp. and are available to the
City. Water use at the site in 2016 was
1,139,800 gallons. The DNR Water
Appropriation Permit for the site allows
up to 20 million gallons to be used each
year
--18 million gallons per year for washing,
and 2 million gallons per year for dust
control.
9. Ground Water
Analysis - DRO
and GRO
None
specified
+ Groundwater samples were analyzed for
DRO. No gasoline is stored on site. If
gasoline storage is added, GRO will be
analyzed. Monitoring results were
included with the application and
reviewed by LBG. DRO was detected in
a sample from 1 of the monitoring wells
in 2016 which did not exceed the Health
Risk Limit. The well was re-sampled
and DRO was not detected in the later
sample. Tiller reported the DRO
detection to the MPCA as required.
10. Map of Index Well
Sites
July 20, 2008 + Map was provided to the City on August
28, 2008.
11. Asphalt Plant
Setback from
Lake
Ongoing + Setback has been maintained as
required by the CUP.
12. Lake Depth Ongoing + Application indicates that the depth of
excavation will not exceed fifty feet
below the water table, per the CUP.
Excavation depth to date was
approximately 15-20 feet into the
groundwater table through 2016.
13. Truck Signage
and Roadway
Cleaning
July 20, 2008 + Washington County has posted Lofton
and Manning Avenues per County
requirements. Tiller has posted signs on
218th Street and at Lofton Avenue to
restrict trucks from using 228th Street
per City of Scandia requirements. The
signs were in place at the City site visit
in 2016.
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 5 February 21, 2017
Condition Deadline
Specified
in CUP
Status Notes
14. Lofton/Highway
97 Intersection
July 20, 2008 + Tiller restricts importing add-rock from
Lofton Avenue during non-daylight
hours per the CUP requirements.
16-19. Updated
Reclamation Plan
July 20, 2008 + Included in application materials;
discussed below.
20. Letter of
Credit/Security
Due before
AOP
approval
+ The financial guarantees are current.
21. AOP Application
Submittal
January 31,
annually
+ Application submitted on January 24,
2017 and determined to be complete.
Dresel Mine Site
The City of Scandia approved a Conditional Use Permit for sand and gravel mining and
processing for Dresel Contracting, Inc. on May 20, 2008. Tiller Corporation now owns and
operates this site, and therefore must also comply with the conditions of the Dresel CUP.
2015 issues are identified in underlined text.
Condition Deadline
Specified
in CUP
Status Notes
1. Comply with CUP Ongoing + In process--monitored by City staff and
consultants.
3. Comply with rules
and regulations
Ongoing + In process--monitored by City staff and
consultants.
4. Permits from
CMSCWD
None
specified
* Received July 10, 2008 and on file at
the City. CMSCWD Administrator
commented on need for District Permit
renewal and wetland replacement—
discussed in text below.
5. Installation of
Monitoring Wells
July 20, 2008 + Installed in May, 2008. Groundwater
Plan was updated to reflect changes to
monitoring well MW -2 in 2013. Site
complied with plan in 2016.
6. Revise Proposed
Conditions Plan Pit
Elevations
July 20, 2008 + City approved a maximum mining
depth at 922 feet-amsl at the Dresel
site, ensuring three feet of separation
between the floor of the mine and the
water table surface during high water
table conditions, based on monitoring
results. LBG review and
recommendations for documentation
of excavation depths are included for
the 2017 AOP.
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 6 February 21, 2017
Condition Deadline
Specified
in CUP
Status Notes
7. Ground Water
Monitoring Plan
July 20, 2008 + Approved in October, 2008 and on file
at the City.
8. Revise Site Plan to
include Index Wells
July 20, 2008 + Provided to City on August 28, 2008.
9. Identify Bench
Mark Elevation
July 20, 2008 + Established at top of Well Casing MW -
1.
10. Ground Water
Analysis - DRO and
GRO
None
specified
+ Samples are analyzed for DRO when
mining activity is occurring. No
gasoline is stored on site. If gasoline
storage is added, GRO will be
analyzed. No DRO or other
contaminants detected in 2016
monitoring at the Dresel site.
11. Signage on 218th
and Roadway
Cleaning
Ongoing + Signage was installed and meets the
CUP requirements; inspected by City
staff during 2016 site visit.
12. Truck Cleaning Ongoing + Trucks must meet requirements for
cleaning per CUP. No issues
identified in 2016.
13. Delineate Northern
Wetland
None
specified
+ Wetland report and delineation
completed. Buffer marked by
September 15, 2008. Complaint
received regarding encroachment into
wetland in late 2014. Agency panel
determined in 2015 that mitigation was
required. Mitigation and replacement
plan were completed and approved by
TEP panel and wetland credits
successfully withdrawn from the
BWSR Wetland Bank in 2016.
14-17. Updated
Reclamation Plan
July 20, 2008 + Reclamation Plan revised as part of
combined Reclamation Plan submitted
for the Tiller site with the AOP
application.
18. Letter of
Credit/Security
Before AOP
approval
+ Financial guarantees are current.
19. AOP Application January 31 + Application submitted on January 24,
2017, and determined to be complete.
OPERATING CONDITIONS - EVALUATION FOR THE AOP
Site Operations - Background Information
The Tiller mine site includes several parcels, as indicated on the Site Plan (Figure C-1).
Excavation activities in 2010-2011 removed material between the Tiller site and former Dresel
Mine site, merging the two sites into one. Tiller mined both sites in 2016. The mining operation
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 7 February 21, 2017
includes removal of overburden, excavation of sand and gravel, crushing, washing, screening,
stockpiling of sand and gravel; recycling of concrete and asphalt products; the production of hot-
mix asphalt and reclamation activities. The overburden is removed from areas to be mined, and
stockpiled on the site for use in reclamation activities. The Scandia Mine operated in past years
on a seasonal basis from mid-April to mid-November, depending on weather conditions. The
opening of the Zavoral Mine extended operations at the Scandia Mine into the winter months to
handle material transported from the Zavoral Mine.
The Applicant indicated that the mining activities within the site will continue to operate as they
have in the past during the 2017 mining season, and will occur on both the Tiller and Dresel
sites. Proposed active mining areas are indicated on the Site Plan (sheet C1). Mining will
occur in both the east and west portions of the Scandia mine and on the Dresel site.
Processing activities will also occur at the site in 2016.
Mining activities ended at the Zavoral Site in 2016, and no additional hauling of class “C” add
rock to the Scandia site from the Zavoral site is anticipated.
Mining into the groundwater began at the site in 2009. This activity has been described in the
previous mining plans for this site, and was evaluated in the Environmental Assessment
Worksheets completed for the Tiller site in 1987 and 1999. Excavation depth to date is
approximately 15-20 feet into the groundwater table. (The CUP allows mining into the
groundwater to a maximum depth of 50 feet.) The AOP application indicates that mining into
the groundwater table occurred in 2013, and did not occur in 2014 or 2015. Mining into the
groundwater table occurred in 2016, and additional mining into the groundwater table may occur
in 2017. Mining in 2016 stayed within the same depth range (15-20 feet into the groundwater
table) as the mining that occurred previously, and the same depth limit is anticipated for 2017.
The equipment that Tiller is using to mine into the groundwater is capable of mining to a
maximum depth of 15-20 feet below grade.
The asphalt plant at the site is equipped with a bag-house air pollutant collection device, and
operates under a Minnesota Pollution Control Agency (MPCA) Air Emissions Permit. Storage
tanks as the site (for fuel and asphalt cement) are regulated by the MPCA.
The main access routes to and from the site are Manning Avenue (County Road 15) and Lofton
Avenue (County Road 1). Both Manning and Lofton are paved. The haul road from Manning
Avenue is paved through the site to the hot-mix asphalt plant and loading area.
Annual Activity
2016 Activity. The application generally includes the data required by the ordinance regarding
annual activity on the site, as follows:
___2015 2016 _____
The amount of material removed from the site: 334,500 Tons 353,000 Tons
Amount of add-rock brought onto the site: 560,500 Tons 272,200 Tons
(2016--201,200 tons of class C add-rock hauled from Zavoral mine to the Scandia mine;
and 71,000 class A and B and D add-rock)
Recycled asphalt and concrete brought to the site: 55,000 CY 55,000 CY
Average number of trips to and from the site each day: 308Trips/day 253 Trips/day*
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 8 February 21, 2017
*The 2013 AOP requires Tiller to report the numbers and source of trucks hauling Class C add-
rock from the Zavoral Mine site and other sites to the Scandia Mine site quarterly to ensure that
additional truck traffic does not result from the Zavoral Site at peak demand concurrently with
other sites.
2017 Activity. The 2017 application anticipates that mining and processing will continue at the
site in 2017. The level of activity will depend on market demand for the site products. The Site
Plan identifies the Potential Mining Areas for 2017, which are on the east and west sides of the
mine floor, and within the approved mining limits.
Ground Water Monitoring Plan and Monitoring Issues
The approved Groundwater Monitoring Plan for the site is on file at the City. The City’s
groundwater consultant, Legette, Brashears, and Graham, Inc. (LBG) reviews the ground water
monitoring results each year for the AOP and provides comments to the City.
LBG Analysis Based on 2016 Monitoring Data
LBG reviewed the data and analytical reports from the monitoring wells on the Tiller site that
were submitted with the application. LBG’s comments noted the following:
2016 groundwater monitoring was completed in accordance with the approved
monitoring plan.
Diesel Range Organics (DRO) were detected at monitoring location PZ-5 during the
September 2016 groundwater monitoring event. Tiller followed property protocol--when
a DRO detection occurs, the samples must be analyzed for Polycyclic Aromatic
Hydrocarbons (PAH). Five PAHs were detected (all were below the MN Department of
Health’s health risk limits). The lab reviewed the raw data and indicated these
detections were biogenic and not from diesel fuel. Tiller sampled the well again in
November 2016 and DRO was not detected. The results were reported to the MPCA.
Rebecca Higgins, MPCA, indicated in a phone call on January 3, 2017 to Tiller that no
further action was needed. LBG concurs with the conclusion and recommendation that
no further action was required.
DRO was not detected above the method detection limit in any of the other wells for
samples collected in September 2016. These results and other groundwater chemistry
results indicate no groundwater quality concerns.
Groundwater flow direction across the site is generally to the north and consistent with
previous submittals;
Groundwater levels in the monitoring wells across the site rose approximately 2 feet
between September 2015 and September 2016. The increase is the result of local and
regional water table fluctuations associated with greater precipitation in 2016 compared
to previous years; therefore, unrelated to mining activities. (LGB’s Graphs showing
groundwater elevations and Excavation Thresholds at the Scandia Mine site are
attached.)
LGB Recommendations
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 9 February 21, 2017
LBG included the following recommendations in their report. The Planner has included the
recommendations in the proposed conditions for the 2017 AOP for the Scandia mine:
It is recommended that Tiller pay close attention to the groundwater levels across
the site in 2017 to ensure the minimum excavation elevation of 922 ft amsl (included
in the CUP for the Dresel site) will not extend below the water table in the event
groundwater levels continue to rise; and
Tiller shall provide the approximate depth of the excavation below the water table in
the 2017 AOP application annual report and future annual reports to confirm that the
excavation did not go below the 865.87 feet amsl threshold.
Tiller also provided groundwater elevations data for the site from September, 2008 to
October 2016 as part of their annual report. The data show that groundwater levels in each
of the sampling locations were approximately 2-3 feet higher in 2016 than in 2008.
Setbacks
The AOP application indicates that the minimum setbacks are maintained as follows:
50 feet from the adjoining property line
200 feet from an existing occupied structure
100 feet from residential property boundaries of 5 acres or less
100 feet from any road right-of-way
The setbacks meet the requirements of Ordinance No. 103. City inspection during 2016
indicated that the setbacks were maintained and meet City requirements.
Fencing
The application indicates that the majority of the site is fenced with 3-strand wire fencing, except
where prohibited due to topography, heavy vegetation and wetlands. There are locking metal
gates at both entrances. The fencing meets the intent of the City’s Ordinance. City staff
reviewed the fencing during the site visit in November, 2016, and verified that it meets the
requirements of the Ordinance and CUP.
Hours of Operation
The site is operated from 7 a.m. to 7 p.m. Monday through Friday, except holidays. The
applicant is required to obtain the City’s permission for any extended hours in accordance with
procedures set in Ordinance No. 103. The City approved extended hours for the operation of
the asphalt plant in June for the Lofton/Highway 97 Project to reduce the potential for traffic
delays, but the extended hours were not needed. The city also approved extended hours in
July 2016 to accommodate city projects, but the hours were not utilized because project
schedules were changed. The City authorized extended hours for the asphalt plant and hauling
in late August 2016 to accommodate the Highway 61/TH 97 Reconstruction Project. The City
received no complaints related to the extended hours.
Screening and Berms
1. Complaint Regarding 218th Street Berm and Modifications in 2015
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 10 February 21, 2017
The City received a complaint from a resident in late 2014 that the berming was no longer
sufficient along 218th Street due to additional excavation in the former Dresel mine site, and
indicated that mining activity was visible from 218th Street. In response to the condition in the
2015 AOP, Tiller constructed a north-south oriented screening berm on the east side of the site
access road to 218th Street during the fall of 2015. The berm was constructed to provide
additional screening from 218th Street and from surrounding properties since the previous berm
was removed to accommodate reclamation. Tiller planted eastern red cedar trees in the fall of
2015 along 218th Street to fill in the gaps in existing screening. Staff reviewed the additional
berming and screening during the site visit in 2016 and determined that it continues to meet the
ordinance requirement.
Dust Control
Major haul roads are hard-surfaced or covered with asphalt millings as dust control measures.
The application indicated that Tiller used a water truck to control dust on unpaved portions of
the site, and calcium chloride was applied to provide dust generated by trucking activity. The
applicant indicated that these actions were implemented in 2016 and will be continued as
needed in 2017. The CUP does not require additional dust control efforts. The City did not
receive complaints about dust control at the site in 2016.
Noise
The Applicant must comply with all Federal, State, and City noise standards. The City received
no noise complaints related to the Scandia Mine in 2016.
Depth of Excavation
The CUP requires that the depth of excavation shall not exceed fifty feet below the water table
(865 feet above mean sea level) on the Scandia Mine site, and may not be lower than 922 feet
above mean sea level (msl) on the former Dresel Mine site. The 2017 AOP application
indicated that mining into the groundwater table occurred in 2016, additional mining into the
water table may occur in 2017. The depth of excavation has been limited to a depth of 15-20
feet within the groundwater table in the past and will continue to be limited to this depth in 2017,
which complies with the limits permitted in the CUP. Based on LBG’s request, the Planner has
included a condition that Tiller report the approximate depth of excavation below the water table
in the 2017 AOP application report and future annual reports.
Site Clearance
Site clearing did not occur in 2016, but may occur within the areas identified on the site plan for
mining activity in 2017. The areas are within the permitted mining limits.
Appearance/Condition
The City’s site inspection in 2016 confirmed that the site and facilities are maintained in a neat
condition.
Sanitary Facilities
The application indicates that site is served by individual sanitary facilities that meet the
requirements of the City’s Ordinance and the Mine Safety and Health Administration. City staff
inspection confirmed that the City’s requirements were met in 2016.
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 11 February 21, 2017
Waste Disposal
The application indicates that waste generated by the operation is disposed of in accordance
with Federal, State and City requirements. The City’s site visit in 2016 confirmed that the
Applicant is meeting the requirements of the CUP.
Water Quality Monitoring Plan
The CUP required that Tiller Corporation complete a plan for groundwater monitoring within 60
days of approval of the CUP (July 20, 2008). The approved ground water monitoring plan was
completed and is on file at the City. Tiller submitted monitoring results for 2016 with its
application for the 2015 AOP. LBG reviewed the ground water monitoring activities and reports,
and indicated that the applicant is completing the required monitoring in compliance with the
CUP. LBG did not recommend a change in conditions for the 2016 AOP.
The monitoring information that Tiller submitted noted that during the September 2016
monitoring event, Diesel Range Organics (DRO) were detected in PZ-5 at a low concentration.
As LBG noted in their report, further analysis indicated that the contaminants were likely
biogenic in origin, and not related to diesel. The well was resampled in November, and DRO
were not detected. The results were reported to the Minnesota Pollution Control Agency
(MPCA). MPCA staff indicated that no further action was needed.
Wetlands and Mitigation
In 2014, the City received a complaint that a wetland located on the Dresel site (now part of the
Scandia Mine site) had been impacted by mining activities.
The WCD completed a site visit in 2015 to document the wetland and buffer conditions on the
site. The site visit included the WCD, Carnelian Marine St. Croix Watershed District, City of
Scandia, and Tiller representatives. The WCD provided direction for wetland replacement
based on the WCA requirements to Tiller.
Tiller provided compensatory mitigation through the purchase of wetland banking credits
through the Board of Water and Soil Resources (BWSR). Tiller purchased credits at a ratio of
2.5:1 to meet the WCA requirements. The WCD provided documentation to the City of the
agency approval of the proposed mitigation through the wetland bank, and confirmation from the
Board of Water and Soil Resources that wetland bank credits have been successfully withdrawn
from state wetland bank #1541 (Freeborn County).
Fuel and Chemical Storage
The application describes fuel and chemical storage at the site. The applicant notes that these
materials are stored in accord with Federal and State standards and County requirements. On-
site fuel storage consists of a 1,000-gallon above-ground storage tank which is located within a
concrete secondary containment area and a 200-gallon above-ground double-walled tank
located next to the standby electrical generator. When production or reclamation crews are
present, an additional 1,000-gallon double-walled tank is brought to the site and used to fuel the
equipment for those operations. All asphalt-cement storage tanks are above-ground. This
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 12 February 21, 2017
includes two 40,000 gallon tanks and two 32,000-gallon tanks. There is also a 20,000 gallon
above-ground used oil storage tank at the site. The used oil is an alternative fuel supply for the
asphalt plant. All tanks containing asphalt cement and used oil are located within a concrete
secondary containment area.
The storage tanks are registered with the MPCA. Storage meets the requirements of the CUP
and agency standards. City staff reviewed the facilities with Tiller staff at the 2016 site visit.
Contingency Response Plan
The application indicates that the site operates under a Spill Prevention, Control and
Countermeasure Plan (SPCC) Plan that was submitted and is on file at the City.
Processing
The CUP application describes the operation of permanent processing equipment on the site,
and indicates that the equipment is operated in accordance with Federal, State and City air
quality, water quality and noise standards. The CUP requires that the asphalt plant and related
structures be set back at least 100 feet from the shore of the proposed lake on the site. The site
visit in 2015 verified that the processing facilities meet the setback requirements of the CUP,
and no violations of permits were reported in 2016.
Trucking Operations
The application indicates that truck operations have access to County Road 15 (Manning
Avenue) and County Road 1 (Lofton Avenue), which are paved roads. The City received no
complaints regarding the trucking activities in 2016.
The Planner’s proposed conditions for the Scandia Mine 2017 are the same as those included
in previous AOP’s and require that Tiller inform all contractors about the following requirements
related to trucking operations, and monitor compliance with the requirements by all of its
contractors:
Engine braking is prohibited in Scandia
Lofton Avenue is restricted to daytime use only
Loads are required to be covered
Asphalt Plant
The site operates a permanent hot-mix asphalt plant that was in operation at the time the City
adopted its mining ordinance. The plant operates under an air quality permit issued by the
MPCA and must meet federal, state and city air, water and noise standards. The City received
no complaints regarding the operation of the asphalt plant in 2016.
Reclamation Plan
The applicant submitted a Reclamation Plan with the AOP application that combines the Tiller
and Dresel site reclamation plans.
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 13 February 21, 2017
Section 8.4 of the City’s Mining ordinance requires the following for reclamation areas:
All banks must be graded or backfilled;
Graded or backfilled areas shall be surfaced with soil of a quality at least equal to
the topsoil of areas immediately surrounding, to a depth at least four inches;
The topsoil shall be planted with trees, shrubs, legumes or grasses
Slopes shall not be steeper than 4:1
Section 8.2 of Ordinance 103 requires the “restoration shall proceed concurrently and
proportional to actual mining operations, and will be subject to review and approval at each
annual inspection and at the end of the permit period.” This section is included in the ordinance
to ensure that:
Large areas of the site are not left in an un-reclaimed state, encouraging erosion,
dust and weed establishment
The mining operation is making an ongoing investment in reclamation, to avoid
potential problems that may occur at the end of the mining operation if a large
investment is needed in reclamation, and the applicant’s resources are limited at that
point, or the applicant abandons the site.
Reclamation activities in 2016 included placement of overburden and suitable fill material in the
area just west of the newly constructed screening berm that runs north-south on the east side of
the site access at 218th Street. Placement of overburden also occurred on portions of the slope
along the west perimeter of the mining area, near the common mining border with the former
Dresel Mine. The reclamation areas are shown on the Site Plan.
Tiller anticipates completing additional reclamation activities on the southern portion of the site
near 218th Street North and in the area along the common mining border with the Dresel Site in
2017. The areas are shown on the Site Plan.
The reclamation completed meets the requirement of the CUP.
Watershed District Comments
The Carnelian-Marine-St. Croix Watershed District reviewed the 2017 AOP application and
provided the following comments:
The Watershed District permit for the Scandia Mine will terminate unless renewed every
five years. Please make the renewal of the Watershed District permit number P08-003 a
conditions of the annual operating permit for this year.
The applicant shall submit a lake monitoring plan for approval, with the first plan that
includes actual lake construction activities. It is our understanding that the mining
activities within the area of the future lake have not been completed. The District will
require a narrative and anticipated timeline for the completion of mining activities in
these areas.
The Planner included the District’s requested conditions in the proposed conditions of approval
for the 2017 AOP.
Complaints Regarding Site Operations
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 14 February 21, 2017
The city received no complaints about operations on the Scandia Mine Site after approval of the
2016 AOP.
SITE INSPECTION
City staff completed a site visit to the Tiller Corporation Scandia Mining Operation on November
16, 2016, including documenting conditions on the site in site photos. The completion of the
wetland replacement and 218th Street berm issues were discussed at the site visit. Findings
from the site visit and discussions related to berm and wetland issues are noted where
appropriate in the items above. Tiller representatives noted that there may be less activity at
the site in 2017 than in 2016, but that activity will depend on market demand.
ACTION REQUESTED:
The City Council can:
1. Approve the AOP;
2. Approve the AOP with conditions;
3. Deny the application if it is found that the request is not consistent with the
Comprehensive Plan, CUP, AOP Criteria, and Mining Ordinance, and is not in the best
interest of the community;
4. Table the request if the Council needs additional information to make its decision.
PLANNING STAFF RECOMMENDATIONS:
The Planner recommends approval of the Tiller Corporation 2017 AOP for sand and gravel
mining and related processing at the Scandia Mine, 22303 Manning Avenue North, with the
following conditions:
1. The applicant shall comply with the conditions of the Conditional Use Permit for sand and
gravel mining and processing at the Scandia Mine site approved on May 20, 2008.
2. The applicant shall pay close attention to the groundwater levels across the site in 2017 to
ensure that the minimum excavation elevation of 922 ft. amsl will not extend below the water
table in the event groundwater levels continue to rise.
3. The applicant shall provide the approximate depth of the excavation below the water table in
the 2017 AOP application annual report and in future annual reports to confirm the
excavation did not go below the 865.87 feet amsl threshold.
4. The applicant shall renew Watershed District permit number P08-003 for the Scandia Mine
as required by the CMSCWD.
5. The applicant shall submit a lake monitoring plan to the CMSCWD for approval with the
renewal of District permit number P08-003.
6. The applicant shall continue to provide the production well records for the site to the City
so the pumping records can be compared to past and future groundwater level trends at
the site. The applicant should measure the water level in the production well under non-
pumping conditions during monitoring periods.
Scandia City Council
Tiller Scandia Mine 2017 AOP Page 15 February 21, 2017
7. Requests for operating hours or haul routes outside those specified in the Conditional Use
Permit shall be accompanied by a proposed truck haul route for approval by staff.
8. The applicant shall inform all of its contractors about the following requirements related to
trucking operations, and monitor compliance with the requirements by all of its contractors:
Engine braking is prohibited in Scandia
Lofton Avenue is restricted to daytime use only
Haul loads are required to be covered
9. The applicant shall regularly monitor the entrances and exits to the site, and work with their
hauling contractors and truck drivers to maintain compliance with traffic laws.
10. The Reclamation activities shall meet the requirements of the Conditional Use Permit,
including soil and planting requirements.
11. If the applicant has knowledge that a crash or traffic violation occurs involving a truck
hauling for Tiller, Tiller shall contact the City to report the incident immediately. The
applicant shall report actions it will take to respond to the incident.
12. The applicant shall pay all fees and escrows associated with this application.
13. This Annual Operating Permit shall expire on March 31, 2018.
ACTION REQUESTED:
Staff request that the Council review this report and approve the AOP at the meeting on
February 21, 2017.