9.a Staff Report Tiller Mine 2020 AOP
Memorandum
To: Scandia City Council Reference: Tiller Corporation— 2020 Annual
Operating Permit Application for
Scandia Mine
Copies To: Ken Cammilleri, City
Administrator
Christina Morrison, Tiller
Corporation
Kirsten Pauley, Sunde
Engineering
Project No.: 17722.000
From: Merritt Clapp-Smith, Planner Routing:
Date: February 11, 2020
SUBJECT: Tiller Corporation, Inc. – 2019 Annual Operating Permit (AOP)
Application for a Mining and Processing Operation
MEETING DATE: February 18, 2020
LOCATION: 22303 Manning Trail. Lengthy legal description provided in
application Attachment 1.
APPLICANT: Tiller Corporation
7200 Hemlock Lane
Maple Grove, Minnesota 55369
60-DAY PERIOD: March 30, 2020
ZONING: Aggregate Mining Overlay District
ITEMS REVIEWED: Application, Plans and Related Submittals; subconsultant and
agency comments, site visit findings
BRIEF DESCRIPTION OF THE REQUEST:
Tiller Corporation has applied for its 2020 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
(CUPs) 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 City Council
Tiller Scandia Mine 2020 AOP Page 2 February 18, 2020
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, to enable permits to 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 former Dresel Mine site to the south. 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 CUPs. Issues and compliance with each are discussed in this report.
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 CUPs 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 that follows. Tiller’s performance is indicated on the table
and in the text sections that follow:
There were no issues identified in 2019 for the Tiller Mine site.
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 3 February 18, 2020
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
* CMSCWD staff reviewed the AOP
application and had no concerns.
CMSCWD Permit 08-003 for the Tiller
mine remains in effect.
5. Monitoring Wells July 20, 2008 + Three required monitoring wells were
installed in 2008. One well was taken out
of service and sealed in 2011 to
accommodate reclamation activities (MW-
2). Monitoring results for the two active
wells in 2019 were provided with the AOP
application and reviewed by LRE Water,
the City’s groundwater consultant.
6. Ground Water
Monitoring
July 20, 2008 + The Ground Water Monitoring 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. The CUP permits mining into
ground water to a depth of 50 feet.
Excavation into the groundwater table has
occurred as follows:
2013 – to a depth of 15 to 20 feet
2014 – no mining into groundwater table
2015 – no mining into groundwater table
2016 – to a depth of 15 to 20 feet
2017 – no mining into groundwater table
2018 – no mining into groundwater table
2019 – to a depth of 15 feet
2020 – excavation into the groundwater
table may occur.
Water level data is collected on an
ongoing basis and submitted to the City.
Water level data has been submitted for
this application, and Dave Hume’s review
and recommended conditions are
discussed in the section on Groundwater
Monitoring.
8. Production Well July 20, 2008 + Production well records are being kept by
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 4 February 18, 2020
Condition Deadline
Specified
in CUP
Status Notes
Records Tiller Corp. and are available to the City.
Water pumped at the site in 2019 was
15,882,400 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
(Diesel Range
Organics) 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 LRE Water. No DRO were detected in
the samples in 2019.
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 (50) feet
below the water table, per the CUP.
Excavation depth to date was
approximately has been less than 50 feet
into the groundwater table through 2019.
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 2019.
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 29,
2020 and determined to be complete.
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 5 February 18, 2020
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.
There were no issues identified in 2019 on the Dresel Mine site.
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
* The CMSCWD Board renewed Permit
08-003 for the Tiller permit in February
2019.
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. The site
complied with plan in 2019.
6. Revise Proposed
Conditions Plan Pit
Elevations
July 20, 2008 + The 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. LRE Water, water quality
consultant to the City of Scandia,
reviewed the submitted data and made
recommendations which are included
for the 2020 AOP.
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 2019
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 2019 site visit.
12. Truck Cleaning Ongoing + Trucks must meet requirements for
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 6 February 18, 2020
Condition Deadline
Specified
in CUP
Status Notes
cleaning per CUP. No issues identified
in 2019.
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. 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.
21. AOP Application
Submittal
January 31,
annually
+ Application submitted on January 29,
2020 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. 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 2019. The mining operation 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 operator brings portable crushing, washing, and
screening plants to the site periodically and these are used to process and stockpile materials.
The operator produces and sells asphalt throughout the construction season and delivers add-
rock materials to site as needed to produce required mixes and materials.
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. The CUP allows mining into the
groundwater to a maximum depth of 50 feet. Mining into the groundwater table occurred in
2013 and 2016, to a depth of 15-20 feet, and did not occur in 2014, 2015, 2017 or 2018. Mining
into the groundwater table occurred in 2019.
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.
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 7 February 18, 2020
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
2019 Activity. The application generally includes the data required by the ordinance regarding
annual activity on the site, as follows:
___2019 2018 ___
The amount of material removed from the site: 425,000 Tons 445,000 Tons
Amount of add-rock brought onto the site: 60,500 Tons 110,520 Tons
Recycled asphalt and concrete brought to the site: 50,000 Tons 50,000 CY
Average number of trips to and from the site each day: 214 Trips/day 242 Trips/day
2020 Activity. The 2020 application anticipates that mining and processing will continue at the
site in 2020. The level of activity will depend on market demand for the site products. The Site
Plan identifies the Potential Mining Areas for 2020, which are within the approved mining limits.
Reclamation: Ongoing reclamation activities are anticipated in the southern portion of the Site,
immediately north and west of the common mining border and within the east half of the mining
area, south of the common mining border during 2020. These areas are shown on Figure 2, Site
Plan as 2020 Potential Reclamation Activity. Some of the areas shown as potential reclamation
will also see active mining during 2020. Once mining is complete, reclamation may advance
into these areas during 2020.
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, LRE Water, reviews the ground water monitoring results each year for
the AOP and provides comments to the City.
Groundwater Quality Analysis Based on 2019 Monitoring Data
LRE Water has reviewed the groundwater monitoring data provided by Sunde for Tiller’s 2020
AOP Application. We do not see any concerns with the 2020 application as it relates to
groundwater quality and quantity.
Tiller’s Scandia Site (Manning Ave.) - 2019 Groundwater Monitoring Data Review Comments
• The 2019 groundwater monitoring was completed in accordance with the approved
monitoring plan;
• Diesel Range Organic (DRO) were not detected above the method detection limit in any
of the groundwater samples collected from the wells in Sept 2019. These results and the
other groundwater chemistry results indicate no groundwater quality concerns;
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 8 February 18, 2020
• Groundwater flow direction across the site is generally to the north and consistent with
previous submittals; and,
• Groundwater levels across the site have continued to rise since about 2014, and level
are 3 to 4 feet higher than they were in 2008. This increase is the result of local and
regional water table fluctuations unrelated to mining operations.
LRE Water Recommendation and Comments
Figure 2 of Sunde’s AOP Application shows a second area where excavation has gone into
the groundwater (see attached). If Tiller plans for this area to remain as a groundwater-fed
lake at the completion of reclamation, the proposed area of the lake shown on Figure 3
should be revised to include this area that has been excavated. There are no concerns with
this second area since it is located within the area that was proposed in the original mining
plan as a future lake.
Tiller should continue to observe groundwater levels during the year. If levels continue to
rise, there is the potential for the water table surface to be above the depth of the excavation
and outside of the limits of the proposed lake. If this occurs, maps submitted in 2020 for the
2021 AOP should identify the general areas where excavation depth is below the water
table.
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 2019
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 on November 5, 2019, 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, Section 7.1(3):
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 9 February 18, 2020
“(3) Hours of Operation. Those portions of the mining operation consisting of excavating,
stockpiling, processing, or hauling shall be conducted only between the hours of 7:00 a.m.
and 7:00 p.m., Monday through Friday, unless other hours or days of operation are
specifically authorized by the City.”
Tiller requested, and the City approved, extended hours one time in 2019, for operation of the
asphalt plant on a Saturday to meet the needs of a Chisago Lakes community center project. In
2018, the city granted extended hours on 14 occasions. Requests for extended hours vary from
year to year, depending on projects and weather.
Screening and Berms
The mine is screened from surrounding areas by berms, wooded areas, and agricultural fields.
The operator planted a large numbers of trees over the years of mine operation to augment the
screening. Processing and stockpiling operations are conducted in recessed portions of the site
to minimize visibility.
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 minimize dust generated by trucking activity. The
applicant indicated that these actions were implemented in 2019 and will be continued as
needed in 2020. The CUP does not require additional dust control efforts.
Noise
The Applicant must comply with all Federal, State, and City noise standards.
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 (amsl) on the former Dresel Mine site. In 2019, excavation into the
groundwater table occurred to a depth of 906 feet amsl on the Scandia Mine site, to obtain
material needed to meet the gradation requirements of the final products. This excavation level
is above the 865 feet amsl allowed on that site.
Excavation into the groundwater table is likely to occur in 2020 based on availability of
equipment. Water level data is collected on an on-going basis and submitted annually to the
City (see Table 1).
Site Clearance
Site clearing did not occur in 2019 but may occur within the areas identified on the site plan for
Potential Mining Activity in 2020. The areas are within the permitted mining limits.
Appearance/Condition
The City’s site inspection in 2019 confirmed that the site and facilities are maintained in a neat
condition.
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 10 February 18, 2020
Sanitary Facilities
The application indicates that the 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 2019.
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 2019 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 2019 with its
application for the 2020 AOP. LRE Water reviewed the ground water monitoring activities and
found that no DRO (diesel range organics) were detected in the samples in 2019.
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 200-gallon above-ground storage tank which is located within a
steel secondary containment area and a 1,000-gallon above-ground double walled tank located
next to the standby electrical generator. When processing and/or reclamation crews are
present, an additional 1,000-gallon double walled tank is brought to the site and used to fuel the
respective equipment.
All asphalt cement storage tanks are above-ground. These tanks consist of two 40,000 gallon
tanks and two 32,000 gallon tanks. There is also a 20,000 gallon above-ground used oil storage
tank. The used oil is utilized as an alternative fuel supply for the asphalt plant. All tanks
containing asphalt cement and used oil are located within a concrete secondary containment
area.
All tanks are registered with MPCA’s Storage Tank Program. MPCA Site ID 51999 is for the
asphalt plant and MPCA Site ID 55016 is for the sand and gravel operation. City staff reviewed
the facilities with Tiller staff at the 2019 site visit.
Small amounts of chemicals utilized by the QM Lab are regulated by Washington County under
United States Environmental Protection Agency (EPA) rules. EPA ID Number MND 981 953 417
has been issued for the site which is classified as a Very Small Quantity Generator.
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. The applicant
notes that the mine operator will comply with other such reasonable requirements that the City
may find necessary to adopt for the protection of health, safety and welfare and/or prevention of
nuisance.
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 11 February 18, 2020
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 equipment is screened from view from other
properties and adjacent roads. 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
2019 verified that the processing facilities meet the setback requirements of the CUP, and no
violations of permits were reported in 2019.
Recycling
Recycling at the site is permitted by Ordinance 103. Asphalt production used approximately
50,000 tons of RAP in 2019. Processed RAP is used in asphalt production and recycled
concrete is sold in various aggregate products.
A Solid Waste Storage Facility license that authorizes the storage of unprocessed concrete,
concrete products and brick and a Recycling Facility license that authorizes the storage and
processing of recycled asphalt products are issued to Tiller by Washington County. General and
Specific Conditions are established for each license and are reviewed on an annual basis and
may include an annual inspection completed by the County.
Trucking Operations
The application indicates that the site has access to County Road 15 (Manning Trail N.), County
Road 91 (Lofton Avenue N.) and 218th Street North. These are hard-surfaced roads. The
operator reported that the average number of trucks travelling to and from the site per day in
2018 was approximately 214 trucks per day.
The Planner’s proposed conditions for the trucking activities at Scandia Mine 2020 AOP 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 2019.
Reclamation Plan
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;
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 12 February 18, 2020
• 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.
Area reclaimed and type of reclamation: Reclamation activities in 2019 included placement of
overburden and suitable fill material in the west half of the mining area, south of the Scandia
Mine/Dresel Mine common mining border. The completed and ongoing reclamation areas are
indicated on Figure 2, Site Plan.
Ongoing reclamation activities are anticipated in the southern portion of the Site, immediately
north and west of the common mining border and within the east half of the mining area, south
of the common mining border during 2020. These areas are shown on Figure 2, Site Plan as
2020 Potential Reclamation Activity. Some of the areas shown as potential reclamation will also
see active mining during 2020. Once mining is complete, reclamation may advance into these
areas during 2020.
The reclamation completed meets the requirement of the CUP.
Watershed District Comments
The Carnelian-Marine-St. Croix Watershed District reviewed the 2020 AOP application and has
no concerns. The CMSCWD permit runs until completion of mine activities, with some
exceptions as identified in the permit. The permit requires the applicant to complete the
following activities on an annual basis:
1. Provide a copy of the annual AOP performance submittals for the City of Scandia, to the
watershed for review.
2. Coordinate a site inspection by the CMSCWD Administrator
3. Reimburse CMSCWD for all expenses associated with implementation of the permit.
SITE INSPECTION
City staff completed a site visit to the Tiller Corporation Scandia Mining Operation on November
5, 2019, including documenting conditions on the site. The site visit reviewed 2019 activities and
site conditions based on the CUP and 2019 AOP and discussed expected activity in 2020.
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 13 February 18, 2020
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 2020 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 comply with site operation hours of 7 a.m. to 7 p.m. Monday through
Friday, except holidays, unless the applicant requests and receives the City’s permission for
extended hours in accordance with procedures set forth in Ordinance No. 103.
3. The applicant shall continue to observe groundwater levels during the year. If levels
continue to rise, there is the potential for the water table surface to be above the depth of
the excavation and outside of the limits of the proposed lake. If this occurs, maps submitted
in 2020 for the 2021 AOP shall identify the general areas where excavation depth is below
the water table.
4. The applicant shall provide the approximate depth of the excavation below the water table in
future annual reports to confirm the excavation did not go below the 865.87 feet amsl
threshold.
5. 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.
6. 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.
7. The applicant shall inform 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
Scandia City Council
Tiller Scandia Mine 2020 AOP Page 14 February 18, 2020
8. 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.
9. The Reclamation activities shall meet the requirements of the Conditional Use Permit,
including soil and planting requirements.
10. 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.
11. The applicant shall pay all fees and escrows associated with this application.
12. This Annual Operating Permit shall expire on March 31, 2021.
ACTION REQUESTED:
Staff request that the Council review this report and approve the AOP at the meeting on
February 18, 2020.