A. LID manual. The LID manual for small sites shall be prepared, maintained, and updated, as deemed necessary and appropriate, by the director and approved by the City Council. It shall set LID standards and practices for storm water pollution mitigation, including urban and storm water runoff quantity and quality control development principles and technologies for achieving the LID standards for projects not otherwise required to implement LID strategies by the MS4 permit. The LID manual for small sites shall also include technical feasibility and implementation parameters, alternative compliance for technical infeasibility, as well as other rules, requirements and procedures as the director deems necessary.
B. Requirements. The site for projects not listed in § 12.16.114(C), but resulting in the creation or addition or replacement of 500 square feet or more of impervious surface area shall be designed to control pollutants, pollutant loads, and runoff volume per the LID manual for small sites. The project applicant shall prepare a small site LID plan which implements set LID standards and practices, as identified in the LID manual for small sites for storm water pollution mitigation, and provides documentation to demonstrate compliance with the LID manual for small sites on the plans submitted to the city. Such a small site LID Plan shall comply with the following:
1. Storm water runoff will be infiltrated, evapotranspired, captured and used, biofiltrated/biotreated through high removal efficiency LID BMP alternatives as identified in the LID manual for small sites, onsite, through storm water management techniques that comply with the provisions of the LID manual for small sites. To the maximum extent feasible, onsite storm water management techniques must be properly sized, at a minimum, without any storm water runoff leaving the site for at least the volume of water produced by the water quality design storm event that results from:
a. The 85th percentile 24-hour rain event determined as the maximized capture storm water volume for the area using a 48 to 72-hour draw down time; or
b. The volume of runoff produced from a 0.75 inch, 24 hour rain event.
2. Pollutants shall be prevented from leaving the site for a water quality design storm event as defined in division B.1. of this section, unless the site has been treated through an approved LID strategy.
3. Any development of four or fewer units intended for residential use shall implement LID BMP alternatives identified in the LID manual for small sites for the residential LID category and provide documentation to demonstrate compliance on the plans and permit application submitted to the city.
4. Any development of five or more units intended for residential use or any development intended for nonresidential use shall implement LID BMP alternatives identified in the LID manual for small sites for the commercial/industrial LID category and provide documentation to demonstrate compliance on the plans and permit application submitted to the city.
5. For any construction activity resulting in an alteration of at least fifty percent (50%) or more of the impervious surfaces on an existing developed site, the entire site must comply with the standards and requirements stated above and with the LID manual for small sites.
6. For any construction activity resulting in an alteration of less than fifty percent (50%) of the impervious surfaces of an existing developed site, only such incremental development shall comply with the standards and requirements stated above and with the LID manual for small sites.
C. Technical infeasibility.
1. When, as determined by the director, the onsite LID requirements are technically infeasible, partially or fully, the infeasibility shall be demonstrated in the submitted small site LID plan, shall be consistent with other City requirements, and shall be reviewed in consultation with the Department of Building and Safety. The technical infeasibility may result from conditions that may include, but are not limited to:
a. Locations where seasonal high groundwater is within five to ten feet of surface grade;
b. Locations within 100 feet of a groundwater well used for drinking water;
c. Brownfield development sites or other locations where pollutant mobilization is a documented concern;
d. Locations with potential geotechnical hazards;
e. Locations with impermeable soil type as indicated in applicable soils and geotechnical reports; and
f. The infiltration rate of saturated in-situ soils is less than 0.3 inch per hour and it is not technically feasible to amend the in-situ soils to attain an infiltration rate necessary to achieve reliable performance of infiltration or bioretention BMPs.
2. If partial or complete onsite compliance of any type is technically infeasible, as determined by the director, the project site and LID plan will be granted a waiver from the requirements of this section and the LID manual for small sites. If a portion of the project site is deemed technically infeasible, the project applicant may propose an equivalent area within the same project area for LID. The director may permit substitutions of equivalent areas upon request by the project applicant.
D. Exemptions from LID requirements. The provisions of this section do not apply to any of the following:
1. A development involving only emergency construction activity required to immediately protect public health and safety;
2. Infrastructure projects within the public right-of-way;
3. A development or redevelopment involving only activity related to gas, water, cable, or electricity services on private property;
4. A development involving only resurfacing and/or re-striping of permitted parking lots, where the original line and grade, hydraulic capacity, and original purpose of the facility is maintained;
5. A project involving only exterior movie or television production sets, or facades on an existing developed site;
6. A project not requiring a City building, grading, demolition or other permit for construction activity.
E. Any development that is exempted from LID requirements under division D. of this section has the option to voluntarily opt in and incorporate into the project the LID requirements set forth herein.
F. City review and plan approval.
1. Prior to the issuance of a permit for a small site, as described in § 12.16.116(B), the City shall evaluate the proposed project using the LID manual for small sites and erosion and grading requirements of the City building official or director to determine (i) its potential to generate the flow of pollutants into the MS4 after construction; and (ii) how well the small site LID plan for the proposed project meets the goals of this chapter. Each plan will be evaluated on its own merits according to the particular characteristics of the project and the site to be developed. Based upon the review, the City may impose conditions upon the issuance of the building permit, in order to minimize the flow of pollutants into the MS4.
2. The director shall approve or disapprove of the small site LID plan within thirty (30) calendar days of submittal, or within thirty (30) days of approval of the development project by the planning commission, where planning commission approval is required. If the plan is disapproved, the reasons for disapproval shall be given in writing to the applicant. Any plan disapproved may be revised by the applicant and resubmitted for approval. A resubmitted plan will be approved or disapproved within thirty (30) days of submittal. No building or grading permit shall be issued until a small site LID plan has been approved by the director.
3. If no building permit has been issued or no construction has begun on a project within a period of one hundred eighty (180) days of approval of a small site LID plan, the small site LID plan for that project shall expire. The director may extend the time by written extension for action by the applicant for a period not to exceed one hundred eighty (180) days upon written request by the applicant showing that circumstances beyond the control of the applicant prevented the construction from commencing. In order to renew the small site LID plan, the applicant shall resubmit all necessary forms and other data and pay a new plan review fee.
G. Transfer of properties subject to the requirements of this section.
1. The transfer or lease of a property subject to maintenance requirements for LID BMPs shall include conditions requiring the transferee and its successors and assigns to either: (a) assume responsibility for maintenance of any existing LID BMP, or (b) replace an existing LID BMP with new control measures or BMPs meeting the then current standards of the City and MS4 permit. Such requirement shall be included in any sale or lease agreement or deed for such property. The condition of transfer shall include a provision that the successor property owner or lessee conduct maintenance inspections of all LID BMPs at least once a year and retain proof of inspection.
2. For residential properties where the LID BMPs are located within a common area which will be maintained by a homeowners' association, language regarding the responsibility for maintenance shall be included in the project's conditions, covenants and restrictions (CC&Rs). Printed educational materials will be required to accompany the first deed transfer to highlight the existence of the requirement and to provide information on what LID BMPs are present, signs that maintenance is needed, and how the necessary maintenance can be performed. The transfer of this information shall also be required with any subsequent sale of the property.
3. If LID BMPs are located within an area proposed for dedication to a public agency, they will be the responsibility of the developer until the dedication is accepted.
(Ord. 2013-11-1462 § 1; Ord. 2013-06-1455 § 5)