San Luis Obispo County |
County Code |
Title 23. COASTAL ZONE LAND USE |
Chapter 23.05. SITE DEVELOPMENT STANDARDS |
§ 23.05.044. Stormwater Pollution Prevention Plan (SWPPP) Required.
Note: Even if the project results in less than one acre of site disturbance, the Regional Water Quality Control Board may require coverage under a General Construction Permit and preparation of a SWPPP if there is a significant water quality impairment resulting from the activity.
a.
Requirement Criteria. Unless exempted by Subsection b, a Stormwater Pollution Prevention Plan (SWPPP) is required prior to issuance of grading and/or construction permits, and/or prior to approval of subdivision improvement plans, for a project that involves clearing, grubbing, grading, or disturbance to the ground such as stockpiling or excavation that:
(1)
Results in site disturbance of one acre or more of land area; or
(2)
Results in site disturbance of less than one acre if the activity is part of a larger common plan of development that encompasses one acre or more of site disturbance.
b.
Exemption from SWPPP preparation. The following projects do not require the preparation of a Stormwater Pollution Prevention Plan (SWPPP):
(1)
Routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of an existing legally established use or development.
(2)
Emergency construction activities required to protect public health and safety.
(3)
Any project exempted from stormwater pollution prevention requirements under a valid waiver or conditional waiver adopted by the State Water Resources Control Board or the Central Coast Regional Water Quality Control Board.
(4)
Agricultural discharges regulated by the State Water Resources Control Board and/or Regional Water Quality Control Board pursuant to waiver and/or formal policy, provided compliance with all relevant permit, waiver, or policy conditions established by the State Water Resources Control Board and/or Regional Water Quality Control Board is maintained.
c.
Coverage under the General Construction Permit. Projects which require preparation of a SWPPP pursuant to this Section shall require coverage to discharge clean stormwater under the General Construction Permit administered by the Central Coast Regional Water Quality Control Board (RWQCB) and State Water Resources Control Board (SWRCB). To gain coverage, the applicant shall submit a Notice of Intent (NOI) or Permit Registration Documents (PRDs) to the SWRCB prior to construction. The SWRCB will issue a Waste Discharge Identification Number (WDID) for approved projects. The SWPPP shall include a copy of the NOI/PRDs and the WDID number. A copy of the SWPPP shall be supplied to the Planning and Building Department.
d.
SWPPP requirements. SWPPPs shall comply with all of the requirements outlined in Sections A, B, and C of SWRCB General Construction Permit Number CAS000002, or any subsequent General Construction Permits that amend or replace Permit CAS000002. These requirements include, but are not limited to those measures set forth in Subsections f through j.
e.
County SWPPP review. At the discretion of the Director and/or Building Official, the County may review and request modifications or amendments to the SWPPP in order to ensure compliance with the County Code and/or the General Construction Permit requirements. At the Director's discretion, a SWPPP may be required to be submitted as part of any discretionary permit review, where a project will meet the thresholds of Subsection a, and where such information is needed to ensure all construction and post-construction measures are appropriately evaluated pursuant to the California Environmental Quality Act (CEQA) and consistent with the LCP
f.
Contents. A SWPPP shall include the following:
(1)
Site Plan. A site plan shall be provided showing the same information required on the following plans:
(i)
Grading plan, pursuant to Section 23.05.038.b.
(ii)
Drainage plan, pursuant to Section 23.05.040.c, with the addition of the following features:
(a)
The anticipated discharge location(s) where the stormwater from the construction site discharges to a municipal separate storm sewer system or other water body.
(b)
Drainage patterns across the project site and as far outside the project site as necessary to illustrate the relevant drainage areas.
(2)
Erosion and Sedimentation Control Plan. A copy of the erosion and sedimentation control plan shall be included with the SWPPP. The erosion and sedimentation control plan shall include the following additional requirements:
(i)
Sediment basin requirements. If a sediment basin is proposed as part of the erosion and sedimentation control plan, the basin shall be designed and maintained pursuant to this Code, provided that the design efficiency is as protective or more protective than the design standards found in the General Construction Permit.
(ii)
Public or private roads. The SWPPP shall include a description of the BMPs to reduce the tracking of sediment onto public or private roads at all times. These public and private roads shall be inspected and cleaned as necessary. Road cleaning BMPs shall be discussed in the SWPPP and will not rely on the washing of accumulated sediment or silt into the stormwater conveyance system.
(3)
Pollutant sources and BMP identification. The SWPPP shall include a description of potential sources of pollutants, including pollutants originating from off-site which may flow across or through areas of construction. Additionally, the SWPPP shall include the following:
(i)
Avoid runoff through construction areas. Runoff from off-site areas shall be prevented from flowing through areas that have been disturbed by construction, unless appropriate conveyance systems and BMPs are in place. BMPs shall consider stormwater run-on and all calculations for anticipated stormwater run-on shall be shown.
(ii)
Stormwater inlets. Show the drainage patterns into each on-site stormwater inlet point or receiving water, and describe or show the BMPs that will protect stormwater inlets and/or receiving waters (e.g. concrete rinse water, slurry from sawcutting, etc.).
(iii)
Contaminated soils or toxic materials. Show or describe the BMPs implemented to minimize the exposure of stormwater to contaminated soil or toxic materials.
(iv)
Staging. Show areas designated for the following: storage of soil or waste; vehicle storage and service areas; construction material loading, unloading, and access areas; equipment storage, cleaning, and maintenance areas.
(v)
Exposure to construction materials/equipment. Describe the BMPs designed to minimize or eliminate the exposure of stormwater to construction materials, equipment, vehicles, waste storage areas, or service areas. The BMPs described shall be in compliance with federal, state, and local laws, regulations, and ordinances.
(vi)
Post-construction BMPs. Describe all post-construction BMPs for the project, and show the location of each BMP on the site plan. Post-construction BMPs consist of permanent features designed to minimize pollutant discharges, including sediment, from the site after construction has been completed. Also, describe the agency or parties to be the responsible party for long-term maintenance of these BMPs.
(vii)
Impaired water bodies. Show the locations of direct discharge from the construction site into any Clean Water Act Section 303(d) listed water bodies. Show the designated sampling locations in the receiving waters, which represent the prevailing conditions of the water bodies upstream of the construction site discharge and immediately downstream from the last point of discharge.
(viii)
Sampling. Show the locations designated for sampling the discharge, associated with contaminated discharges other than sediment. Samples shall be taken if visual monitoring indicates that there has been a breach, malfunction, leakage, or spill from a BMP which could result in the discharge of pollutants that would not be visually detectable, or if stormwater comes into contact with soil amendments or other exposed materials or contamination and is allowed to be discharged. Describe the sampling procedure, location, and rationale for obtaining the uncontaminated sample of stormwater.
(4)
Additional sources of pollutants and identification information.
(i)
Narrative description. The SWPPP shall include a narrative description of pollutant sources and BMPs that cannot be adequately communicated or identified on the site map. In addition, a narrative description of preconstruction control practices (if any) to reduce sediment and other pollutants in stormwater discharges shall be included.
(ii)
Inventory of materials and activities. The SWPPP shall include an inventory of all materials used and activities performed during construction that have the potential to contribute to the discharge of pollutants other than sediment in stormwater. Describe the BMPs selected and the basis for their selection to eliminate or reduce these pollutants in the stormwater discharges.
(iii)
Runoff. The SWPPP shall include the following information regarding the construction site surface area: the size, the runoff coefficient before and after construction, and the percentage that is impervious before and after construction.
(iv)
Construction schedule. The SWPPP shall include a construction activity schedule which describes all major activities such as mass grading, paving, parcel improvements at the site, and the proposed time frame to conduct those activities.
(v)
Responsible person(s). The SWPPP shall list the name and telephone number of the qualified person(s) who have been assigned responsibility for pre-storm, post-storm, and storm event BMP inspections. The qualified person(s) that is/are assigned responsibility shall ensure full compliance with the permit and implementation of all elements of the SWPPP. This shall include the preparation of the annual compliance evaluation and the elimination of all unauthorized discharges.
(5)
Non-stormwater management.
(i)
Describe all non-stormwater discharges to receiving waters that are proposed for the construction project. Non-stormwater discharges shall be eliminated or reduced to the extent feasible. Include the locations of such discharges and descriptions of all BMPs designed for the control of pollutants in such discharges.
(ii)
Discharging sediment-laden water which will cause or contribute to an exceedance of the applicable RWQCB's Basin Plan from a dewatering site or sediment basin into any receiving water or storm drain without filtration or equivalent treatment is prohibited.
(6)
Post-construction stormwater management.
(i)
The SWPPP shall include descriptions of the BMPs to reduce pollutants in stormwater discharges after all construction phases have been completed at the site (Post-Construction BMPs).
(ii)
The permit holder must consider site-specific and seasonal conditions when designing the control practices.
(iii)
Operation and maintenance of control practices after construction is completed shall be addressed, including short-and long-term funding sources and the responsible party.
(7)
Maintenance, inspection, and repair. The SWPPP shall include a discussion of the program to inspect and maintain all BMPs as identified in the site plan or other narrative documents throughout the entire duration of the project. Inspections are to be completed by the responsible party designated by the permit holder. The program shall include the following provisions:
(i)
Responsible person(s). The name and contact information for the responsible person(s).
(ii)
Inspection timing. Inspections shall be performed before and after storm events, and once each 24-hour period during extended storm events, to identify BMP effectiveness and implement repairs and/or design changes.
(iii)
Inspection checklist. For each required inspection, the permit holder shall complete an inspection checklist, using an inspection checklist provided by the Regional Water Quality Control Board, and/or State Water Resources Control Board, or on a form containing equivalent information.
(iv)
Repairs. All corrective maintenance to BMPs shall be performed as soon as possible after the conclusion of each storm depending upon worker safety. Repairs or design changes shall be completed as soon as feasible.
(8)
Training. Individuals responsible for SWPPP preparation, implementation, and permit compliance shall be appropriately trained, and the SWPPP shall document all training. This includes those personnel responsible for installation, inspection, maintenance, and repair of BMPs. Those responsible for overseeing, revising, and amending the SWPPP shall also document their training. Training should be both formal and informal, occur on an ongoing basis when it is appropriate and convenient, and should include training/workshops offered by the SWRCB, RWQCB, or other locally recognized agencies or professional organizations.
(9)
Contractors and subcontractors. The SWPPP shall include a list of names of all contractors (or subcontractors) and individuals responsible for implementation of the SWPPP. This list shall include telephone numbers and addresses. Specific areas of responsibility of each subcontractor and emergency contact numbers shall also be included.
(10)
Incorporation by reference. This SWPPP may incorporate by reference the appropriate elements of other plans required by local, state, or federal agencies. A copy of any requirements incorporated by reference shall be kept with the SWPPP at the construction site.
(11)
Certification by the preparer. The SWPPP and each amendment shall be signed by the landowner (permit holder) or his representative and include the date of initial preparation and the date of each amendment.
g.
Monitoring and reporting program. The SWPPP shall include a monitoring and reporting program meeting the following standards:
(1)
Annual certification. Each permit holder or qualified assigned personnel listed by name and contact number in the SWPPP must certify annually that construction activities are in compliance with the requirements of the General Construction Permit and the SWPPP. This certification shall be based upon the site inspections required by Subsection f(7). The certification must be completed and submitted to the Department of Planning and Building and to the RWQCB by September 1 of each year.
(2)
Noncompliance reporting. Permit holders who cannot certify compliance, in accordance with Subsection g(1) and/or who have had other instances of noncompliance excluding exceedances of water quality standards as defined in Section 23.05.048.d(2) (Receiving Water Limitations), shall notify the County and the Central Coast RWQCB within 30 days. Corrective measures shall be implemented immediately following discovery that water quality standards were exceeded. The notifications shall identify the noncompliance event, including an initial assessment of any impact caused by the event; describe the actions necessary to achieve compliance; and include a time schedule subject to the modifications by the RWQCB indicating when compliance will be achieved. Noncompliance notifications must be submitted within 30-calendar days of identification of noncompliance.
(3)
Monitoring records. Records of all inspections, compliance certifications, and noncompliance reporting must be retained for a period of at least three years from the date generated.
(4)
Monitoring program for sedimentation/siltation. Projects that may discharge stormwater into a threatened or impaired water body are subject to the following standards. A water body is considered threatened or impaired if it appears on the most recent list prepared pursuant to Section 303(d) of the Clean Water Act. Projects which discharge to tributaries that do not appear on the list of threatened or impaired water bodies, or that flow into a municipal separate storm sewer system (MS4) are not subject to these sampling and analysis requirements.
(i)
Sampling and analysis program. The permit holder shall conduct a sampling and analysis program for the pollutants (i.e. sedimentation/siltation or turbidity) causing the impairment. The permit holder shall monitor for the applicable parameter.
(ii)
Sedimentation or siltation. If the water body is listed for sedimentation or siltation, samples shall be analyzed for Settleable Solids (ml/l) and Total Suspended Solids (mg/l). Alternatively or in addition, samples may be analyzed for suspended sediment concentration according to ASTM D3977-97.
(iii)
Turbidity. If the water body is listed for turbidity, samples shall be analyzed for turbidity, in terms of Nephelometric Turbidity Units (NTUs).
(iv)
Relationship to BMPs. The sampling and analysis parameters and procedures must be designed to determine whether the BMPs installed and maintained prevent discharges of sediment from contributing to impairment in receiving waters.
(v)
Collection of samples. Samples shall be collected during the first two hours of discharge from rain events which result in a direct discharge to any threatened or impaired water body. Samples shall be collected during daylight hours (sunrise to sunset). Permit holders need not collect more than four (4) samples per month. All samples shall be taken in the receiving waters and shall be representative of the prevailing conditions of the water bodies. Samples shall be collected from safely accessible locations upstream of the construction site discharge and immediately downstream from the last point of discharge.
(vi)
Laboratory analysis. For laboratory analysis, all sampling, sample preservation, and analyses must be conducted according to test procedures under Title 40 of the Code of Federal Regulations, Part 136. Field samples shall be collected and analyzed according to the specifications of the manufacturer of the sampling devices employed. Portable meters shall be calibrated according to manufacturer's specification. All field and/or laboratory analytical data shall be kept in the SWPPP document, which is to remain at the construction site at all times until a Notice of Termination has been submitted and approved.
(5)
Monitoring program for pollutants not visually detectable in stormwater. A sampling and analysis program shall be developed and conducted for pollutants which are not visually detectable in stormwater discharges, which are or should be known to occur on the construction site, and which could cause or contribute to an exceedance of water quality objectives in the receiving water. The program shall comply with the following provisions:
(i)
Construction sites. Examples of construction sites that may require sampling and analysis include:
(a)
sites that are known to have contaminants spilled or spread on the ground; or
(b)
sites where construction practices include the application of soil amendments, such as gypsum, which can increase the pH of the runoff; or
(c)
sites having uncovered stockpiles of material exposed to stormwater.
(ii)
Pollutants. Pollutants that should be considered for inclusion in this sampling and analysis program are those identified as required by Subsections f(3) and f(4).
(iii)
Materials. Construction materials and compounds that are not stored in water-tight containers under a water-tight roof or inside a building are examples of materials for which the permit holder may have to implement sampling and analysis procedures.
(iv)
Collection of samples. Visual observations before, during, and after storm events may trigger the requirement to collect samples. Any breach, malfunction, leakage, or spill observed which could result in the discharge of pollutants to surface waters that would not be visually detectable in stormwater shall trigger the collection of a sample of discharge. Samples shall be collected at all discharge locations which drain the areas identified by the visual observations and which can be safely accessed. A sufficiently large sample of stormwater that has not come in contact with the disturbed soil or the materials stored or used on-site (uncontaminated sample) shall be collected for comparison with the discharge sample. Samples shall be collected during the first two hours of discharge from rain events that occur during daylight hours and which generate runoff.
(v)
Qualified personnel. For sites where sampling and analysis is required, personnel trained in water quality sampling procedures shall collect stormwater samples.
(vi)
Comparison to uncontaminated sample. The uncontaminated sample shall be compared to the samples of discharge using field analysis or through laboratory analysis. Analyses may include, but are not limited to, indicator parameters such as: pH, specific conductance, dissolved oxygen, conductivity, salinity, and totally dissolved solids (TDS).
(vii)
Laboratory analysis. For laboratory analysis, procedures shall comply with Subsection g(4)(vi).
(6)
Additional requirements. The County and/or RWQCB may require the permit holder to conduct additional site inspections, to submit reports and certifications, or perform sampling and analysis.
h.
Implementation.
(1)
The SWPPP shall be developed prior to the start of soil disturbing activities and shall be implemented concurrently with the commencement of soil disturbing activities.
(2)
The site shall be maintained consistent with the stormwater pollution prevention standards of Section 23.05.048.d.
(3)
For ongoing construction activity involving a change of ownership of property, the new owner shall review the existing SWPPP and amend if necessary, or develop a new SWPPP within 45-calendar days.
i.
Availability. The SWPPP shall remain on the construction site while the site is under construction during working hours, commencing with the initial construction activity and ending with termination of coverage under the General Construction Permit (Notice of Termination).
j.
Changes. Whenever there is a change in construction or operations which may affect the discharge of pollutants, the SWPPP shall be amended with the County and RWQCB.
(1)
The SWPPP shall be amended if the permit holder violates any standard in this Section or a condition of the General Construction Permit or has not achieved the general objective of reducing or eliminating pollutants in stormwater discharges. If the County and/or RWQCB determines that the permit holder is in violation of this ordinance or the General Construction Permit, the SWPPP shall be amended and implemented in a timely manner, but in no case more than 14 calendar days after notification by the County and/or RWQCB. All amendments shall be dated and directly attached to the SWPPP.
(2)
The County and/or RWQCB may require the permit holder to amend the SWPPP.
[Added 2013, Ord. 3253]
Editor's note
See editor's note, § 23.05.020.