Loading...
922 & 922M, New SFR and garage, Staff Reports (2)•ol Ra&09 ge& I INCORPORATED JANUARY 24, 1957 NO. 2 PORTUGUESE BEND ROAD ROLLING HILLS, CA 90274 (310) 377-1521 FAX (310) 377-7288 0 POPPY TRAIL PROJECT AND PROPERTY LOCATED AT 1 POPPY TRAIL City of Rolling Hills, California SECOND ADDENDUM TO MITIGATED NEGATIVE DECLARATION, AUGUST 15, 2017 Project Description: This document is a Second Addendum to the Mitigated Negative Declaration (the "MND") for the remediation of a 2005 landslide which originated from 1 Poppy Trail Road. The displacement of dirt caused by the landslide affected two adjacent lots. During the remediation process, and following several lot line adjustments between the affected parcels, two lots were eventually created: 0 Poppy Trail Road and 1 Poppy Trail Road. Following the landslide, the City of Rolling Hills and the Rolling Hills Community Association undertook various improvements and, between April and October of 2010, detailed project plans were developed for remediation of the failed slope. (Hereinafter referred to as the "Landslide Remediation Project."). The purpose of the remediation was to remediate the failed slope and to allow for future development of the site with single family homes. With relation to the Landslide Remediation Project, the City Council adopted a resolution in 2010 approving a variance to disturb 65% of the net lot area of what is now 0 Poppy Trail Road and 55% disturbance of the net lot area of what is now 1 Poppy Trail. Pursuant to an updated survey of 0 Poppy Trail Road, the existing disturbance is actually 78.95%. There is no additional disturbance planned for the proposed project at 0 Poppy Trail Road; any slight grading that will be conducted in connection with the proposed project at 0 Poppy Trail Road consists of smoothing and evening out the existing building pad. An updated survey was not conducted for the lot known as 1 Poppy Trail, as there is no development application pending; however, staff believes that the disturbance of the lot located at 1 Poppy Trail also exceeds the percentage that was reported relative to the Landslide Remediation Project. A rough estimate of the disturbance of the second lot (according to staff) is also about 78% of the new lot area. The overall purpose of this Second Addendum is to modify the minor technical discrepancy between the approved disturbance percentage (65%) and the actual -1- • • disturbance percentage (78.95%) for 0 Poppy Trail and the approved disturbance (55%) and the estimated disturbance percentage of 1 Poppy Trail. There is a pending development application for 0 Poppy Trail Road; the lots for both 0 and 1 Poppy Trail Road have been remediated to allow for the development of one single family residence on each lot. There will be no environmental impact from the grading or development of a single family home, therefore it will not cause new significant impacts not identified in the previously certified MND or result in a substantial increase in the severity of previously identified significant impacts related to the Landslide Remediation Project. -2- • • TABLE OF CONTENTS I. INTRODUCTION 4 A. LANDSLIDE REMEDIATION PROJECT 4 B. PROJECT MODIFICATION REGARDING 0 POPPY TRAIL 5 C. PROPOSED MODIFICATION REGARDING 1 POPPY TRAIL 6 D. ADDENDUM PURPOSE & NEED 6 II. DESCRIPTION OF PROJECT MODIFICATION & NECESSARY ACTIONS 8 III. ENVIRONMENTAL ASSESSMENT 9 A. GEOLOGY & SOILS 10 B. AIR QUALITY 11 C. BIOLOGICAL RESOURCES 11 D. CULTURAL RESOURCES 11 E. HAZARDS & HAZARDOUS MATERIALS 12 F. HYDROLOGY & WATER QUALITY 12 G. NOISE & VIBRATION 12 H. RECREATION 13 I. TRANSPORTATION & TRAFFIC 13 J. UTILITIES & SERVICE SYSTEMS 13 IV. CONCLUSION 14 -3- • • I. INTRODUCTION A. LANDSLIDE REMEDIATION PROJECT On March 5, 2005, a landslide originating from the property located at 1 Poppy Trail Road caused a large amount of dirt to be displaced. Following the landslide, the City of Rolling Hills and the Rolling Hills Community Association undertook various improvements and, between April and October of 2010, detailed project plans were developed for remediation of the failed slope. In the summer of 2010, a preliminary geotechnical finding and analysis was prepared (relative to the slope failure and repair), as well as a review of the grading plan and tentative parcel map. These reports were prepared by GMU Geotechnical, Inc. and were reviewed and approved by Willdan Engineering, the City's contracted Building and Safety/Public Works Engineers. By the fall, of 2010, the California Joint Powers Insurance Authority ("JPIA") had requested discretionary approval from the City in order to (1) subdivide the land in question into two single-family residential lots fronting Poppy Trail Road; (2) allow for a lot line adjustment; (3) allow for a grading plan; (4) allow for a zone change; (5) allow for a site plan review; and (5) seek variances to repair the slope failure. (Hereinafter collectively referred to as the "Landslide Remediation Project.") Specifically, with relation to the variances, the JPIA sought a variance from the City's requirement that a maximum of 40% of any lot be disturbed;1 in order to remediate the landslide and to create residential building pads and access thereto, the JPIA proposed to disturb no more than 65% of the net lot area of 0 Poppy Trail Road and 55% of the net lot area for 1 Poppy Trail Road. Additionally, the JPIA sought variances in order to construct retaining walls, grade steeper slopes, provide a set -aside for a future stable and corral in the front yard of 0 Poppy Trail Road, and export 5,000 cubic yards of dirt. In connection with the Landslide Remediation Project, the JPIA prepared an Initial Study and determined that, with the implementation of mitigation measures, no negative effect on the environment would result. Therefore, an MND was prepared; on October 4, 2010, the City Council approved the MND. (Hereinafter referred to as the "2010 MND.") In December of 2010, prequalified contractors were invited to submit bids related to the Landslide Remediation Project. During this time, the JPIA determined that it would be possible to reduce or eliminate some of the retaining walls through selected modifications of the grading plan and proposed its modifications related thereto to the City. These project modifications comprised four main elements: (1) a reduction in the number and height of the walls for the project by increasing the slope steepness; (2) additional dirt to be exported from the site; (3) reduction in grading quantities for remediation of the slopes; and (4) changes in the landscape plan consistent with the See Section 17.16.070(B) of the Rolling Hills Municipal Code which limits the amount of disturbance on a lot to forty percent of the net lot area. -4- • • proposed slope modifications. The City determined that the modifications proposed by the JPIA to the Landslide Remediation Project would require Planning Commission approval, an amendment to the resolution of approval related to the site plan review, and an addendum to the 2010 MND. Following geotechnical review of the revised grading plan for 0 and 1 Poppy Trail Road, the first addendum to the 2010 MND was processed and approved by the City Council on February 28, 2011. (Hereinafter referred to as the "First Addendum.") Collectively, the 2010 MND and First Addendum may be referred to as MND. On July 19, 2011, a revised corrective grading and geogrid configuration was considered relative to the Landscape Remediation Project. Similarly, on October 5, 2012, a report of geotechnical observation and testing of the Landslide Remediation Project was prepared. These reports were again prepared by GMU Geotechnical and were reviewed and approved by Willdan Engineering. Furthermore, with relation to the Landslide Remediation Project, the Los Angeles County Building Department conducted intense geotechnical evaluations with respect to the soil, hydrology, geology, compaction, and excavation of the site. Pursuant to these studies, it was concluded that the methods proposed by the Landslide Remediation Project would result in safe and stable parcels suitable for development. B. PROJECT MODIFICATION REGARDING 0 POPPY TRAIL The proposed project at 0 Poppy Trail Road consists of a new 4,859 square foot residence with 1,000 square feet of covered porches, a 1,232 square foot garage, a 96 square foot service yard, a 560 square foot pool and spa, a 220 square foot detached solid -roof covered patio and outdoor kitchen, a 64 square foot enclosed space for pool equipment, a 54 square foot gatehouse leading to an outdoor courtyard with a 100 square foot fountain, and overall grading of 2,726 cubic yards. (Hereinafter referred to as the "0 Poppy Trail Project.") An updated survey conducted by the 0 Poppy Trail Project engineer concluded that the existing disturbance of the lot is 78.95%; not 65%, as was previously calculated with relation to the Landslide Remediation Project. There is no additional disturbance planned for the 0 Poppy Trail Project. The slight grading, which consists of smoothing and evening out the building pad, will take place on the existing building pad. Two recent reports prepared relative to the 0 Poppy Trail Project indicated that the building pad created by the remediation is safe for construction and the percolation testing for the proposed septic tank indicate that the geologic conditions on the site are adequate for construction of the proposed septic system. As this building pad was previously graded and disturbed with relation to the Landslide Remediation Project, the 0 Poppy Trail Project does not introduce potentially significant environmental impacts that were not addressed in the 2010 MND. C. PROPOSED MODIFICATION REGARDING 1 POPPY TRAIL 1 Poppy Trail is currently vacant and the City has not received a development application at this time. An updated review conducted by City staff indicates that the existing disturbance of this lot is closer to 78%; not 55%, as was previously calculated -5- • • with relation to the Landslide Remediation Project. An updated survey, as well as geotechnical and percolation reports, will be required before any development could be approved on 1 Poppy Trail. With that said, however, the Landslide Remediation Project included creating a building pad on 1 Poppy Trail; therefore, no additional disturbance will be necessary. For these reasons (explained in further detail below) future development of 1 Poppy Trail Road will not introduce potentially significantly environmental impacts that were not addressed in the MND. D. ADDENDUM PURPOSE & NEED In order to account for the discrepancy between the disturbance calculations in the Landslide Remediation Project and the 0 Poppy Trail Project, the applications for both Projects were thoroughly compared. In doing so, City staff noted that the Landslide Remediation Project calculations for the property located at 0 Poppy Trail Road failed to take into consideration a disturbed area which existed prior to the 2005 landslide. Additionally, these calculations failed to account for the disturbance of the area necessary for future construction of a stable and corral. When considered together, the existing disturbance area prior to the 2005 landslide and the set aside area for the future construction of a stable and corral account for approximately 4.6% of the lot. Therefore, the disturbance for 0 Poppy Trail which should have been reported with relation to the Landslide Remediation Project is 69.6%. Lastly, in comparing the actual plans which delineate the lot disturbances for both Projects, the disturbances for the Landslide Remediation Project and the 0 Poppy Trail Project are nearly identical (with the exception of the 4.6% described above). In order to account for the discrepancy between the disturbance calculations in the Landslide Remediation Project and the 1 Poppy Trail Road parcel, the "as graded plans" prepared at the final stages of the Landslide Remediation Project and the originally submitted plans for the remediation were thoroughly compared. In doing so, City staff noted that the Landslide Remediation Project calculations for the property located at 1 Poppy Trail Road failed to take into consideration a disturbed area, which existed prior to the 2005 landslide. Additionally, these calculations failed to account for the disturbance of the area necessary for future construction of a stable and corral. When considered together, the existing disturbance area prior to the 2005 landslide and the set aside area for the future construction of a stable and corral account for approximately 5% of the lot. Therefore, the disturbance for 1 Poppy Trail which should have been reported with relation to the Landslide Remediation Project is 60%. The purpose of this addendum is to reconcile the new information (i.e. the variation in disturbance area) and demonstrate that the deviation does not change the conclusions in the MND such that the MND can be used by decision makers in making the discretionary decision as to whether or not to approve the project. Typically, single family homes are exempt from CEQA review under 15303 (new construction of small structures). Due to the existence of the landslide on the site, the City is relying on the MND prepared for the Landslide Remediation Project (which acknowledged this future -6- • • development on the site) to confirm that there will be no significant environmental impacts from the project. The information presented above indicates that the proposed modifications to the Landslide Remediation Project relative to the disturbance percentage constitutes a minor technical change pursuant to Section 15164 (b) of the CEQA Guidelines and does not represent a substantive change to the Project or the circumstances in which the Landslide Remediation Project (or any future site development) will be undertaken, nor would the changes introduce potentially significant environmental impacts that were not previously addressed in the adopted MND. The California Environmental Quality Act ("CEQA") and CEQA Guidelines establish the type of environmental documentation that is required when changes to a project occur after a project has been approved. Section 15164 (b) of the CEQA Guidelines states that: "An addendum to an adopted negative declaration may be prepared only if minor technical changes or additions are necessary or none of the conditions described in Section 15162 calling for the preparation of a subsequent EIR or negative declaration have occurred." Section 15162 of the CEQA Guidelines states that preparation of a subsequent EIR or negative declaration is required when there are substantial changes proposed to a project, or substantial changes occur with respect to circumstances, or new information becomes available which could lead to new significant environmental effects or a substantial increase in the severity of previously identified significant effects. Likewise, California Public Resources Code ("PRC") Section 21166 states that unless one or more of the following events occur, no subsequent or supplemental environmental impact report shall be required by the lead agency or by any responsible agency: • Substantial changes are proposed in the project which will require major revisions of the environmental impact report; • Substantial changes occur with respect to the circumstances under which the project is being undertaken which will require major revisions in the environmental impact report; or • New information, which was not known and could not have been known at the time the environmental impact report was certified as complete, becomes available. This Second Addendum analyzes the 78.95% disturbance for the 0 Poppy Trail Project and a disturbance in excess of 55% on 1 Poppy Trail, and potential environmental impacts associated therewith in light of the environmental impacts identified for the Landslide Remediation Project. As discussed in the sections that follow, for all environmental issues, the Second Addendum demonstrates that the disturbance on both lots would not result in new significant impacts not identified in the Landslide Remediation Project's previously certified MND or substantially increase the severity of previously identified impacts such that a supplemental or subsequent environmental -7- • • impact report is required. As presented below, none of the conditions described in State CEQA Guidelines section 15162 calling for the preparation of a subsequent environmental document has occurred. As a result, and addendum is the appropriate CEQA document for analysis and consideration of the proposed project modification. II. DESCRIPTION OF PROTECT MODIFICATION & NECESSARY ACTIONS This Second Addendum, along with the First Addendum and the 2010 MND, are intended to cover all discretionary approvals that may be required to construct or implement the Landslide Remediation Project and development of single family homes on the site. The following discretionary actions are addressed by this Second Addendum, and are added to those discretionary approvals listed in the Landslide Remediation Project's 2010 MND (as amended on February 28, 2011). The 0 Poppy Trail Project includes the construction of a single family residence, including amenities and structures appurtenant thereto; as such, the Project is categorically exempt from CEQA under Class 3, Section 15303 ("New Construction"). However, while the updated survey related to the 0 Poppy Trail Project calculates a necessary disturbance of 78.95% - for which the project applicant is seeking a variance - the restrictions imposed by the Landslide Remediation Project preclude any disturbance on the 0 Poppy Trail property in excess of 65%. Therefore, in order for the City to properly process and consider the appropriateness of the variance requested by the 0 Poppy Trail Project applicant, the disturbance percentage must be accurate. With that said, the calculations made with relation to the Landslide Remediation Project do not include the existing disturbance area prior to the 2005 landslide, the set aside area for the future construction of a stable and corral, and the changes in the soil from 2011 to the present reflected in the current condition of the property. The allowable uses for 1 Poppy Trail include the construction of a single family residence, as well as any amenities and structures appurtenant thereto; development of this kind would also be categorically exempt from CEQA under Class 3, Section 15303 ("New Construction"). However, Staff's review of the Landslide Remediation Project has indicated that residential development on 1 Poppy Trail would require a disturbance in excess of 55% - which is prohibited by the development conditions imposed relative to this lot. In anticipation of any future development project at 1 Poppy Trail Road, the disturbance percentage must be accurate. With that said, the calculations made with relation to the Landslide Remediation Project do not include the existing disturbance area prior to the 2005 landslide, the set aside area for the future construction of a stable and corral, and the changes in the soil from 2011 to the present reflected in the current condition of the property. This Second Addendum is required to correct a minor technical discrepancy between the approved disturbance percentages (65% and 55%) and the actual disturbance percentages (78.95% and 78%) for 0 Poppy Trail and 1 Poppy Trail, respectively. As indicated by the geotechnical studies of the landslide remediation project and as shown on the geological, grading and drainage plans for the landslide remediation project, the -8- • • limit of remediation (thus disturbance), plus the disturbance of the areas of the lots prior to the remediation calculate to the 78.95% and 78% of the net lot area for each lot and not to the previously reported 65% and 55% disturbance. Reviewing these documents, one can state with certainty that the area of disturbance as currently calculated for each lot have been addressed in the MND and the remediation methodology proposed and implemented by the Landslide Remediation Project included all these areas. Therefore, a modification to address the minor technical discrepancy between the approved disturbance percentage (55%) and the actual disturbance percentage (approximately 78%) will not cause new significant impacts not identified in the 2010 MND or result in a substantial increase in the severity of previously identified significant impacts related to the Landslide Remediation Project such that a supplemental or subsequent environmental impact report is required. III. ENVIRONMENTAL ASSESSMENT The potential environmental impacts associated with the discrepancy between the actual disturbance percentages relative to the approved disturbance percentages for 0 Poppy Trail and 1 Poppy Trail identified within the 2010 MND for the Landslide Remediation Project are discussed below for each environmental issue area analyzed in the 2010 MND. The comparative analysis (1) discusses whether impacts are increased, decreased, or unchanged from the conclusions discussed in the 2010 MND; and (2) addresses whether any changes to mitigation measures are required. The 2010 MND and this Second Addendum found less than significant impacts to occur to the following environmental issue areas included in the State CEQA Guidelines Appendix G Environmental Checklist: Aesthetics, Agricultural Resources, Archeological Resources, Land Use/Planning, Mineral Resources, Population/Housing, Public Services, Mandatory Significance Findings, and Greenhouse Gas Emissions; therefore they are not discussed in this Second Addendum. This second Addendum is required to correct a minor technical discrepancy between the approved disturbance percentages (65% and 55%) and the actual disturbance percentages (78.95% arid 78%) for 0 Poppy Trail and 1 Poppy Trail, respectively. The environmental issue area that the proposed disturbance percentage change may affect the most is Geology and Soils - which is addressed first, followed by the remaining issues. A. GEOLOGY Sr SOILS Based on the exploration, testing, and analysis conducted with relation to the Landslide Remediation Project, it was determined that the failed portions of the slope could be repaired such that the lots could be redeveloped for residential use without adverse impacts to adjacent properties. Therefore, with relation to the 2010 MND, no mitigation measures were provided beyond the recommendations provided by the consultants and engineers for the Project. These recommendations included excavation of a keyway within the bedrock and removal of all failed material on the slope; removal of existing fill and colluvial soils where the slope was to be re -graded; placement of geogrids for reinforcement and stability; construction of seepage pits; construction of MSE walls, and retaining walls. -9- • • A change in the disturbance percentages would have no bearing on the remediated landslide area for which an MND and First Addendum were prepared and approved by the City. The 0 Poppy Trail Project consists of the construction of a single family residence and accessory structures which do not alter or change the previously approved scope of the Landslide Remediation Project (including the retaining walls, slopes, bridle trails, streets or building pads whichwere repaired or constructed in connection therewith). In reviewing the 0 Poppy Trail Project, a discrepancy was noted with regard to the calculation of the disturbance percentage on the lot. As explained in further detail above, a variance was granted to the JPIA for the purpose of landslide remediation to disturb 65% (this percentage was more than the 40% maximum allowed by Section 17.16.070(B) of the Rolling Hills Municipal Code). Notwithstanding the reported disturbance, prior remediation of the site involved extensive geotechnical and geological evaluation and scrutiny. These studies included (1) a June 16, 2012 preliminary geotechnical finding and analysis (related to the slope failure and repair); (2) an August 6, 2010 report of geotechnical studies and review of the grading plan and parcel map; (3) a February 21, 2011 geotechnical review of revisions to the grading plan and parcel map; (4) a July 19, 2011 revised corrective grading and geogrid configuration; and (5) an October 5, 2012 report of geotechnical observation and testing of landslide repair grading. These studies indicate that the landslide remediation resulted in a safe and buildable lot. With the new proposal for development on the remediated parcel and on the existing building pad, the project engineer for the 0 Poppy Trail Project calculated that the disturbed area of the lot is actually closer to 79%; this calculation includes the disturbance for a future stable and corral. There is no additional disturbance planned for either the 0 Poppy Trail Project or the 1 Poppy Trail parcel; any grading for residential development on either parcel will be slight and will consist of smoothing and evening out the existing building pads. The Landslide Remediation Project calculations for the property located at 0 and 1 Poppy Trail Road failed to take into consideration a disturbed area which existed prior to the 2005 and the set aside area for the future construction of a stable and corral on each lot. Thus this is an exercise to verify the conclusions are correct and there is no physical change to the environment that will result (other than building the home on the pad- which is generally exempt from CEQA). Overall, changing the approved disturbance percentage to the actual disturbance percentage does not represent a substantive change to the Landslide Remediation Project or the circumstances in which the Project will be undertaken, nor would the changes introduce significant impacts or substantially worsen previously identified impacts with regard to geology and soils. Therefore, there would be no geological impacts and no new mitigation measures would be necessary. B. AIR QUALITY -10- • • The project modification would not result in changes to construction equipment, durations or use, vehicle trips, or the types of construction activities described in the 2010 MND. This is because the project modification will not increase the number of days that construction occurs or increase the intensity of construction analyzed in the MND. There is no additional disturbance planned for the 0 Poppy Trail Project. The slight grading, which consists of smoothing and evening out the building pad, will take place on the existing building pad. Because the building pad was created for future construction on the 1 Poppy Trail lot, no addition disturbance is anticipated for that lot as well, should it be developed in the future. The underlying construction of a single family home is typically exempt and does not create air quality impacts. The underlying grading and remediation has already been done. Therefore, there would be no changes in emissions described in the 2010 MND and no new mitigation measures would be necessary. C. BIOLOGICAL RESOURCES The project modification would not increase impacts to habitat or species as it would not result in increased structural area, fill or construction activities. The slight grading, which consists of smoothing and evening out the building pad, will take place on the existing building pad. Furthermore, the project modification does not propose any development in the Sensitive Environmental Area previously designated by the Landslide Remediation Project. The underlying construction of a single family home is typically exempt and does not create impacts to biological resources. The underlying grading and remediation has already been done. Therefore, there would be no biological impacts and no new mitigation measures would be necessary. D. CULTURAL RESOURCES The project modification would not cause a substantial change in the significance of an archaeological resource; destroy a paleontological resource or unique geological feature; or disturb any human remains. The extensive soil excavation and remediation activities undertaken with regard to the Landslide Remediation Project did not result in the discovery of significant unique archaeological resources and have already taken place. The development proposed for the 0 Poppy Trail Project, and any future development of 1 Poppy Trail, will take place solely upon the previously created building pads. The underlying construction of a single family home is typically exempt and does not create impacts to cultural resources. The underlying grading and remediation has already been done. Therefore, the project modification would not result in new impacts and no new mitigation measures are required. E. HAZARDS & HAZARDOUS MATERIALS The project modification does not change the nature of the hazardous materials that will potentially be released by the 0 Poppy Trail Project or a future development on 1 Poppy Trail. The project modification would not result in a change of hazardous materials used or handled, and would not result in additional sources or quantities of hazardous material. The underlying construction of a single family home is typically exempt and -11- • • does not create hazards and hazardous materials impacts. The underlying grading and remediation has already been done. Therefore, the project modification would not result in new impacts and no new mitigation measures are required. F. HYDROLOGY & WATER QUALITY The proposed modification would not result in the increased potential for discharges or any changes to the water quality or hydrology impacts described in the 2010 MND, and no new impacts have been identified. The underlying construction of a single family home is typically exempt and does not create hydrology and water quality impacts. The underlying grading and remediation has already been done. Therefore, no new mitigation measures are required. G. NOISE & VIBRATION The 2010 MND evaluated the primary sources of construction noise (i.e., heavy equipment and truck traffic). The extensive excavation and remediation activities undertaken with regard to the Landslide Remediation Project have since concluded (resulting in two safe and stable parcels suitable for development). The development proposed for the 0 Poppy Trail Project, and any future development of 1 Poppy Trail, will take place solely upon the previously created building pads, so necessary truck trips will be significantly less than those analyzed with relation to the Landslide Remediation Project. Furthermore, any construction noise and vibration generated by residential development on these lots will be considered "normal" and will not be in excess of local standards/ordinances; and will not increase either existing or ambient noise levels. The underlying construction of a single family home is typically exempt and does not create noise and vibration impacts. The underlying grading and remediation has already been done. Therefore, the project modification would not result in new impacts and no new mitigation measures are required. H. RECREATION The proposed modification will not impact the enhancements already made to the two equestrian trails, Poppy Trail Road, the two bridle trails or riding rings. The development proposed for the 0 Poppy Trail Project, and any future development of 1 Poppy Trail, will take place solely upon the previously created building pads. The underlying construction of a single family home is typically exempt and does not create recreation impacts. The underlying grading and remediation has already been done. Therefore, the project modification would not result in new impacts and no new mitigation measures are required. I. TRANSPORTATION & TRAFFIC -12- • The project modification would not result in increased traffic. Truck and worker vehicle trips for the overall project were assessed in the 2010 MND and work on either the 0 Poppy Trail Project or any future project at 1 Poppy Trail Road would not increase the total trip calculations. This is because the project modification will not increase the intensity of construction analyzed in the 2010 MND. The underlying construction of a single family home is typically exempt and does not create transportation and traffic impacts. The underlying grading and remediation has already been done. The project modification would not conflict with applicable congestion management programs for designated roads or highways nor result in additional traffic impacts or require new mitigation measures. J. UTILITIES & SERVICE SYSTEMS The project modification would not exceed wastewater treatment requirements of the applicable Regional Water Quality Control Board, or require construction of new water or wastewater treatment facilities. Most homes in the City of Rolling Hills are on individual septic systems, and the 0 Poppy Trail Project is proposed to be served through an individual septic system. In fact, the percolation testing for the proposed septic tank indicates that the geologic conditions on the site are adequate for construction of the proposed septic system.2 Additionally, should 1 Poppy Trail Road be developed in the future, it too will be served through an individual septic system. Furthermore, the proposed modification will not require construction of new storm water drainage facilities and there are sufficient water supplies and landfills to serve both parcels when developed. IV. CONCLUSION Based on the foregoing, the analyses conducted and the conclusions reached in the previously certified MND remains valid, and no supplemental environmental review is required for the change in disturbance from 65% to 78.95% for 0 Poppy Trail and greater than 55% for 1 Poppy Trail. These modified disturbance percentages would not cause new significant impacts not identified in the previously certified MND or result in a substantial increase in the severity of previously identified significant impacts. No changes have occurred with respect to circumstances under which the Landslide Remediation Project was undertaken (or the associated residential development) that would cause significant environmental impacts to which the change in disturbance to 78.95% (for 0 Poppy Trail) and greater than 55% (for 1 Poppy Trail) would result in a cumulatively considerable contribution. There is no new information that shows that these changes in disturbance would cause new significant environmental impacts that were not already analyzed in the previously certified version of the MND. Therefore, pursuant to CEQA Guidelines Section 15164, no supplemental environmental review is required beyond this Second Addendum. 2 See May 24, 2017 Report of Percolation Resting for Proposed Septic System, Geotechnical Engineering Services — 0 Poppy Trail, Rolling Hills, California prepared by GMU Geotechnical, Inc.; see also May 11, 2017 Geotechnical Foundation and Structure Design Parameters — 0 Poppy Trail, Rolling Hills, California prepared by GMU Geotechnical, Inc. -13-