1986 an Evaluation of Alternative Technique for Mitigating Impacts Of
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I I fihtsrL,sf, I ffiJ-T'j I AN EVALUATION OT' ALTERNATIVE TECHNIQUES FOR MITIGATING IMPACTS OF TIIE SAN ONOFRE t NUCLEAR GENERAIING STATTON I I t I Richard F. Ambrose Mari-ne Science Institute University of California I Santa Barbara, California 93106 I I I I Prepared for: Marine Review Committee, fnc. 53I Encinitas BIvd., Suite J.05 T Encinj.tas, California 92024 I February, 1986 I I t AN EVALUATTON OF ALTERNAUVE TECHNTQUES FOR MITIGATTNG IUPACTS OF THE SAN ONOFRE NUCLEAR GENERJATINGSTATION TABLE OF CONTENTS EXECUTIVE SI'MMARY aaaaaaaaaaaaaaa ii O.O PREFACE vi 0.1 Purpose of this report ............... vii O.2 Previous work on rnitigation by the MRC vii,i 1.0 INTRODUCTION ..,............ ....... 1 1.1 Mitigation ..... .......... .. r... 1 1.1.1 Definition and General Application I 1.1.2 Procedure in California ..... ..... 6 1.1.3 Application to SONGS 7 L.2 Irnpact Evaluation at SONGS 9 9 13 L4 L7 18 18 I 24 2.I.3 Benthic Invertebrates 33 2.L.4 Plankton 35 2.2 Resource Substitution: Out-of-kind l,titir gation 37 I 2.2.1 Habitat Restoration ..... .. o.. 38 2.2.2 Coastal preservation 4t 2.2.3 Information Acquisition ..... ..... 42 I 2.2.4 Monetary payrnents ..... .o... 43 2.2.5 Water euality Improvement ......... o...... o.... 45 2.3 Mitigation Banking .o..........o.................... 46 prevention 2.4 Loss ..... 48 I 2.4.L rntake .................. r r r.....,... 49 2.4.2 Discharge ............... ...,...... 52 2.4.3 Cooling Towers ............. o.... r. 35 t 2.4.4 Restriction of Operations ..................... 55 2.5 Summary and Discussion .......... ..... 58 3.0 RECOMMENDATIONSFOR FUTURE SrUDY . O" " .... 63 4.0 LITERATURECITED .............................. 73 I TABLESAND FTGURES ........o........... ..... 85 Appendix I. Mitigation policy of the U.S. Fish and Wildl ife Senrice .. ...... .. .. .. AL I Appendix 2. Sumnrary of Habitat Evaluation Method.s (including HEp and others) 423 Appendix 3. Correspondence with U.S. Fish I and Wildlife Ser:rrice .. .. o A28 Appendix 4. List of species at San Onofre Kelp Bed 432 Appendix 5. Technigues for establishing kelp beds aaaaaaaaa 448 Appendix 6. Techniques for restoring coastal wetlands A'52 I Glossary a a a a a a a aaata a a aa oa aaaaa a a a a aa a a... a a a a G1 I I I EXECUTIVE SUMI{ARY This report presents an overview of options available for mitigating the possible effects of the san onofre Nuclear Generating Station (soNGS), and evaluates the appropriateness of each option. The three types of mitigation techni.ques consid,ered, are: (1) those replacing lost resources with identical resources (in-kind compensation) , (2) those substituting d,ifferent resources for the rost resources (out-of-kind compensation), and (3) those avoiding or minirnizing the loss of resources (Ioss prevention). Mit'igation is a process designed. to nininize the loss of resources or compensate for unavoidable resource losses that result from human activity. The ultirnate objective pf the mitigation process is to maintain the functional and productive capacity of the ecosystem, while accomod,ating necessary d.evelopment of natural resources. The U.S. Fish and Wildlife Service has an official nitigation policy that establishes the framework for mitigation and. priorit,izes rnitigation planning goals on the basis of the value of the resource; in calj.fornia, the other government agencies involve6 in nitigation in the marine environment folIow the same general philosophy as FWS. The fundamental principles guiding the FWSpolicy are that avoidance or compensation be reconmend,ed for the most valued, resources, and, the degree of rnitigation reguested correspond to the value and scarcity of the resource at risk. Two different kinds of rnitigative compensation are recognized: in-kind replacement of 11 resources involvinlt resources that are physically and. biologically similar to those being altered and that play sirnirar roles in ecosystem function, and out-of-kind substitution or resources involving dissiruilar resources. The most preferred, type of compensation is in-kind replacement of species at the location of the inpact ("on-sitet,). The FWSrnitigation poricy focuses on losses of rrhabitat valuerr. However, a broader perspective may be necessary to evaluate nitigation in an open coast ecosystem. In-kind replacement of resources that are lost due to the operation of SoNGsrnight be accomplished by enhancing existing kelp beds, creating new kelp beds, constructing artificial reefs, constructing fish hatcheries, restoring fish nursery habitats, constructing invertebrate hatcheries, or manipulating natural habitats. In-kind, replacernent of resources is the most preferred method of compensationr so these techniques should be consid.ered for the majority of the resources and/or the most varuable resources. The techniqrres that seem best for application at SONGS are (1) creating a kelp bed, and (2) constructing an artificiar reef. out-of-kind substitution of lost resources could be acconplished by any of the in-kind techniques, or by habitat (especially wetland) restoration or enhancement, preserx/ation of coastal 1ands, information acquisition, or water quality improvement. For resources that cannot feasibly be replaced by in- kind techniques, out-of-kind techniques must be used to achieve compensation. The three out-of-kind, technigues that seem best for 111 application at soNGS are (1) restoring or enhancing a habitat, (2) acguiring inforrnation, and (3) acquiring and preserving coastal Iand. The prevention of resource losses is generally the most favored technj-que for rnitigation. However, loss prevention technigues at SONGScannot be integrated. into project planni.ng or construction. Two loss prevention technigues, the Fish Return System and velocity caps, have already been implemented. at sONGs. Implementing other techniques involving structural changes to SoNGS would involve unknowns in the areas of engineering, biorogical effects, and economics. Two loss prevention techniques that do not reguire structural changes are: restricting the flow rate of water through the cooling system, and shutting down operations d,uring seasons of high potential impact. It is not clear that seasonal restriction of operations wourd, be effective at soNGS. There are many unknowns associated with the techniques discussed in this report, making it difficult to evaluate their feasibility for use at soNcs. I have reconmend.ed,three stud.ies that will assess the feasibility of the most pronising mitigation techniques. Fj.rst, r recornrnend,stud.ying the feasibility of creating kelp beds. Techniques used, for establishing keJ.p. and the potential of different locations could be evaluated.. second, r reconmend studying the production of fish on artificial reefs. The relationship between fish production on natural versus artificial reefs could be investigated by surrreys of natural and, artificial reefs. Additional stud.ies of Pendleton Artificial Reef would also 1V be useful, and the MRCnight consider beconing involved in the planning and monitoring of large-scale experimental reefs to be built by the Department of Fish and Game. Final1y, r recommend determining the critical life stages of fish species at risk at SONGS. Identifying potential life-history bottlenecks through a detailed review of existing information would aid in evaluat,ing the feasibirity of utirizing fish hatcheries or restoring nursery habitat to compensate for fish losses. Finalry, r note that the lack of information about possible nitigation techniques is a significant obstacle to evaluating their feasibility, yet previous rnitigation efforts have not been studied closely. f suggest that, regardless of the technigue(s) chosen, the MRCrecornmend. appropriate evaluative stud.ies be cond,ucted.. A glossary of terms related to nitigation is includ,ed. v PREFACE The Marine Review Committee has been charged with d.eterrnining the effects of the cooling system of the san onofre Nuclear Generating station (soNcs) on the surrounding marine biota. Initially, the aim of the MRC was to provid.e information to the California coastal Comrnission (ccc) concerning possible changes in the cooring systern of soNGS to prevent or red.uce any ad.verse effects to the marine environment. rn Lg7g, the cornmission recognized that some effects rnight be mitigated, without requiring changes in the cooling system, as indicated by the following excerpt from staff reconmendat,ions (Fischer 1979): n1he Commission also recognizes that operational changes or rnitigation measures night adequately compensate for any marine life damages resulting from the operation of Units 2 and 3. The Cornmission, therefore, requests the MRC to study the feasibility and. effects of selected, prornising nitigation measures, including construction of an artificial reef, as suggested by Southern California Edison. The MRC should recommend what measures rnight be taken to assure there would be no net adverse effect, on the marine environment from operation of soNGS units 2 and 3.r The MRC began investigating arternat,e mitigation measures in 19g0. rn 1994, the commission requested (Tobin, June 8, L984) that the MRC rfreview the work done to date on nitigation and determine if any additional mitigation research is appropriate. At the end of MRC study, the comrnittee should be able to recommend sound, feasible rnitigation measures for proj ect impacts . rl 0.1 Purpose of this report The present project, ItA Study of Mitigationrr, was undertaken to summarize the rerevant work on rnitigation in the marine