Chapter 4 — QUARRY EXCAVATION STANDARDS

The intent of this Chapter is to provide standards for the extraction of mineral resources.

(Ord. 2024-18, § 1(Exh. A), 2024)

Approved Quarry Excavation Permits shall be subject to the regulations adopted by the State Mining and Geology Board as authorized by the California Surface Mining and Reclamation Act (SMARA) of 1975 (Public Resource Code Section 2710 et seq.), as amended; Public Resource Code Section 2207; and the California Code of Regulations adopted pursuant thereto (Title 14, 3500 et seq.).

(Ord. 2024-18, § 1(Exh. A), 2024)

Any Quarry Excavation Permit approved under the provisions of this Title shall be subject to the following standards:

(a)

Permitted Accessory Uses. Quarry excavations may include the use of equipment, structures, and facilities necessary or convenient for the extraction, processing, storage, and transport of materials, including, but not limited to:

(1)

Separation plants;

(2)

Rock crushers;

(3)

Concrete batching plants;

(4)

Asphalt batching plants; and

(5)

Recycling facilities that recycle material into asphalt concrete, Portland cement concrete, aggregate base, sand, gravel, fill dirt, or other products that are determined by the Director to be common to the aggregate industry.

Permitted Accessory Uses shall not be initiated unless approved by the Review Authority as a part of a new Quarry Excavation Permit or separately approved by the Director as an addition to a previously approved Quarry Excavation Permit. The Director shall require the applicant to submit an Improvement Plan, as provided in Section 9-8-2801, with fees as specified by resolution of the City Council, in order to secure approval for the permitted accessory use.

(b)

Stockpiling. No stockpiled soil or material shall be placed closer than twenty-five (25) feet to a property boundary except as provided for in Subsection (m);

(c)

Private Roads. All private roads involved in an excavation shall be maintained so as to control the creation of dust. The first one hundred (100) feet of any private road on the property which intersects with a publicly maintained road shall be surfaced in a manner approved by the Director. Traffic-control and warning signs shall be installed, if required, at such intersection. The placement and size of these signs shall be approved by the Director of Public Works;

(d)

Erosion Control. Protective vegetative planting, silt screen dams, or other approved methods shall be required where necessary for the control of erosion. An erosion and sediment control plan approved by Development Services Division shall be part of the reclamation plan;

(e)

Performance Standards. Standards contained in Chapter 5 of Division 10 shall be met;

(f)

Hours of Operation:

(1)

Normal Hours. Plant operations shall normally be carried on during the hours from 5:00 a.m. and 9:00 p.m.

(2)

Time Zone. Said hours shall be based on either Pacific Standard Time or Pacific Daylight Savings Time, whichever is legally in effect.

(3)

Exceptions. Exceptions may be made:

(A)

For periods of declared national, state, or County emergency, or

(B)

If a finding can be made by the Review Authority that the longer hours of operation will not cause a nuisance in the case of a specific quarry excavation.

(4)

Extension of Hours. Normal operating hours may be extended if the Director of the Community Development Department determines that the extended hours of operation are necessary to meet the operational need of a specific project, provided:

(A)

Any request for extension in the hours of operations shall be made in writing to the Director of the Community Development Department and include:

(i)

The reason for the extended hours of operation,

(ii)

The hours of extended operation and the day the extended operations are to commence and terminate, and

(iii)

A copy of the bid specifications, contract terms, or other similar applicable documents, if applicable.

(B)

The request shall be approved or disapproved by the Director of the Community Development Department within three (3) business days following the day on which the request is filed.

(i)

If approved, the Director may impose conditions on the extended hours which are appropriate to reduce disturbance to the public or residents in the area of the quarry.

(ii)

Notice of the approval and conditions shall be sent to all property owners in the area.

(C)

The applicant shall reimburse the Community Development Department for all costs associated with the request.

(g)

Replacement of Topsoil. In agricultural areas, the topsoil shall be set aside, and upon completion of an excavation, the topsoil shall be replaced and the site leveled in conformance with the excavation permit. This requirement may be waived if the property is to be rehabilitated for a use other than agriculture which

is consistent with the General Plan, or if a soils report indicates the replacement of the topsoil will not enhance the agricultural suitability of the property. In such cases, the topsoil may be removed from the site;

(h)

Weed Control. If noxious weeds are on the site, operations shall be in accordance with instructions from the Agricultural Commissioner of San Joaquin County;

(i)

Health Considerations. Quarry excavations shall:

(1)

Not cause health or sanitary hazards and shall not create conditions which will cause the breeding or increase of mosquitos, rodents, or other pests.

(2)

Provide an approved potable water supply for all employees.

(3)

Provide approved toilets for all employees (chemical toilets are acceptable).

(4)

Provide handwashing facilities on or near the approved toilets.

(j)

Setbacks. No excavation shall take place within twenty-five (25) feet of any property line or right-of-way (nor within the allowed slopes adjacent to said twenty-five (25) foot setback), unless the elevation prior to excavation is more than that of the abutting property, in which case the elevation within said twenty-five (25) foot setback shall at no time be less than that of the abutting property, at the property line;

(k)

Slopes. The following provisions do not apply to temporary interior cut slopes (i.e., working slopes that do not fall within any of the criteria listed below). Temporary interior cut slopes shall comply with the Cal OSHA Code of Regulations and/or the Federal OSHA Code of Regulations as applicable.

(1)

Terracing Required. All slopes over fifty (50) feet in height shall be terraced with a maximum vertical distance between terraces of fifty (50) feet. Each terrace or bench shall be a minimum of twelve (12) feet wide.

(2)

Terrace Drainage.

(A)

Drainage plans with calculations shall be submitted for approval to Development Services Division for all terraces as part of the Reclamation Plan.

(B)

Terraces for reclaimed final slopes shall be sloped back towards the fill and be designed such that runoff is directed to collection points where it can enter catch basins and be conveyed via pipes or other acceptable conveyance to the toe of slope. The spacing of collection points shall be no greater than 1,500 feet, with each reclaimed final slope face that has terracing shall have a minimum of one (1) down drain. The method of transporting the water along the flow line of the terrace to the down drain, so as to prevent erosion and possible slope failure, shall be approved by the Development Services Division.

(C)

The method of drainage of terraces for temporary slopes at setback lines shall be submitted to Development Services division for approval.

(3)

Slope Modification Requirement.

(A)

The Review Authority may require slopes flatter than those specified below for safety or aesthetic purposes if the proximity of residential and other urban uses, waterways or roads, the instability of materials, or the surrounding terrain so warrants.

(B)

If after one (1) year or more of extraction the approved slope does not remain stable, the Review Authority shall have the authority to reduce the slope or require other appropriate measures in the immediate area and other areas as deemed necessary in order to correct the condition as well as require the operator to correct the deteriorated slope.

(4)

Slope Stability Factors of Safety. When required in this Title to provide site-specific geologic and engineering slope stability analysis, the following minimum slope stability factors of safety shall apply:

(A)

A minimum factor of safety of 1.5 against static deep seated failure.

(B)

A minimum factor of safety of 1.5 against static surficial failure.

(C)

A minimum factor of safety of 1.1 against seismic failure;

(5)

Temporary Cut Slopes at Setback Lines. Temporary cut slopes (i.e., for limited periods of time, slopes that are in the process of extraction prior to being backfilled) at setback lines shall not exceed one (1) foot horizontal to one (1) foot vertical, except that temporary cut slopes at setback lines to a maximum of onehalf (½) of a foot horizontal to one (1) foot vertical may be maintained if site-specific geologic and engineering analysis demonstrate through a slope stability analysis that the proposed temporary cut slopes will have a minimum slope stability factor of safety as required in Section 9-1415.3(k)(4). However, in the event that there are existing structures on the adjacent property (or the immediate potential for structures on the adjacent property), the excavation shall at not time be closer to the property line than a line projected on a slope of one (1) to one (1) from the property line to the toe of slope.

(6)

Final Slopes. Final cut and/or fill slopes shall not exceed two (2) feet horizontal to one (1) foot vertical, except as specified below:

(A)

Final slopes to a maximum of one and one-half (1½) feet horizontal to one (1) foot vertical may be maintained when site-specific geologic and engineering analysis demonstrate through a slope stability analysis that the proposed final slopes will have a minimum slope stability factor of safety as required in Section 9-1415.2(k)(4), while demonstrating suitability for the proposed end use and protecting against erosion (by means of revegetation or other methods approved by Development Services Division).

(B)

Final slopes to a maximum of one (1) horizontal foot to one (1) foot vertical may be maintained under water (beginning five (5) feet below the lowest water table on the property experienced in the preceding three (3) years) when site-specific geologic and engineering analysis demonstrate through a slope stability analysis that the proposed saturated slopes will have a minimum slope stability factor of safety as required in Section 9-1415.2(k)(4);

(7)

Fill Slopes. Fill slopes shall be constructed consistent with recommendations from a qualified civil/geotechnical engineer based upon site-specific geologic conditions;

(l)

Fencing. Fencing four (4) feet in height consisting of not less than three (3) strands of barbed wire, or an approved equivalent, shall be placed around the excavation area where slopes steeper than two (2) feet horizontal to one (1) foot vertical are maintained. Six (6) foot high security fencing or an approved equivalent shall be required where slopes steeper than two (2) feet horizontal to one (1) foot vertical are created, if the proximity of such slopes to residential uses or other uses involving a concentration of people so warrants;

(m)

Screening and Landscaping:

(1)

Where an open pit operation is visible from a public road right-of-way or property zoned or shown on the General Plan for residential development, screening consistent with Chapter 6 of Division 10 is required;

(2)

The Review Authority may approve the use of a landscaped berm to screen the pit provided that an adequate setback for maintenance is provided and sight distance at road intersections is not impaired.

(n)

Ponding. All water utilized in the plant operation shall be disposed of behind a closed dike unless an alternative method is approved by the Review Authority;

(o)

Excavation/Reclamation Schedule. The reclamation plan (as required in Section 9-854) shall show the phases of excavation. Reclamation on one phase of an excavation shall be initiated prior to the start of the next excavation phase. The final reclamation of any phase of excavation shall be completed within two (2) years of the commencement of the reclamation process. Excavation shall be limited so that at any point of time a maximum of one phase is being reclaimed while one phase is being excavated;

(p)

Time Limitation. The Review Authority may place a time limit on the Quarry Excavation Permit or any phase of the Permit. Absent any specific time limitation, the Quarry Excavation Permit shall remain in effect as long as the excavation continues in compliance with the approved Permit;

(q)

Annual Inspection Reports. The applicant shall pay a fee to the City to cover the cost of annual inspections of the excavation to ensure compliance with the conditions of the permit and the reclamation plan. The County may use professional services as provided for in Section 9-240.11. The consultant shall be selected by the City of Mountain House. Upon completion of the annual inspection, the person in charge of the mining operation shall submit to the State Geologist and the City a report which shall contain all the information as required by Section 2207 of the Public Resources Code. Additional inspections may be conducted, but the cost of additional inspections shall be paid for by the applicant only if noncompliance with the conditions of the Quarry Excavation Permit or the reclamation plan is found;

(r)

Performance Guarantee. In order to ensure reclamation of the site, compliance with conditions of approval, and compliance with County and State mining regulations, the applicant shall provide performance guarantees as a condition of the issuance of the Quarry Excavation Permit. The amount and form of the guarantee shall be subject to annual review and approval by the City and the State, and the amount shall be adequate to ensure reclamation of disturbed land and/or land to be disturbed during a given phase. The

annual review of the financial guarantee shall be coordinated with the annual inspection and approval of successive reclamation security so that the guarantee includes the amount of disturbed land plus the amount of land estimated to be disturbed during the next twelve (12) months, less the amount of land previously determined by the Department of Public Works annual inspection to have been reclaimed. The performance guarantee shall be in the form of either: 1) a surety bond, 2) a trust fund with the lead agency, or 3) an irrevocable letter of credit. Any interest accrued in a trust fund shall stay with the trust fund account. The financial guarantee shall be payable to "City of Mountain House and the Department of Conservation" under the applicable provisions of the City and the state mining regulations. The financial guarantee shall be callable by the City or the state under the following circumstances:

(1)

The applicant causes the excavation to become idle (as defined in Section 9-1-304) without an approved interim management plan;

(2)

The applicant files for bankruptcy;

(3)

The County or state determines on the basis of annual inspections and reports that the applicant has not maintained substantial compliance with the approved Permit;

(4)

There arises an occurrence or circumstance which, in the opinion of the City or state, jeopardizes the site reclamation; or

(5)

The State makes one or more of the findings specified in Section 2774.4(a) of the State Public Resources Code.

In any instance that the City or state makes the demand for partial or full tender of the financial guarantee of performance, the City and/or state may use all or any portion of the financial guarantee to reclaim the site and to recover its administrative costs associated therewith.

(s)

Exception to Operating Conditions. The Review Authority may grant an exception to any operating condition contained herein, except the requirement of a reclamation plan. A written report will be required to show that such exception will not result in a hazardous condition, the cost of strict compliance would be unreasonable in view of all the circumstances, and such exceptions will not adversely affect the environment, property, or persons in the area. Such request shall be filed with the original or a subsequent application and shall include a complete statement of justification;

(t)

Enforcement. Except as otherwise provided in State Mining Regulations, the City shall have authority to enforce provisions of the Surface Mining and Reclamation Act. The County may exercise all enforcement regulations available under the City Development Title and the State Public Resources Code. Such enforcement measures include charging the applicant the costs of administering an enforcement action. The basis for charging fees for an enforcement action shall be a time and materials compensation; and

(u)

Groundwater Conditions. An evaluation of the impact of resource extraction on groundwater conditions shall be required for all quarry excavations which extend to depths below the groundwater level of the uppermost aquifer.

(Ord. 2024-18, § 1(Exh. A), 2024)

DIVISION 15. - NATURAL RESOURCES REGULATIONS

CHAPTER 1. - NATURAL RESOURCES REGULATIONS: INTENT AND ORGANIZATION