Butte County Clerk of the Board

2008 BOARD OF SUPERVISORS MEETING CALENDAR

chapter one

Introduction and summary

1.1 Introduction

The "Chico Urban Area Nitrate Compliance Plan" addresses the contamination of groundwater in the Chico Urban Area by nitrate, a form of nitrogen. The discharge from individual septic systems has been cited by the Central Valley Regional Water Quality Control Board (Regional Board) as the primary source of groundwater nitrate concentrations that exceed the drinking water standards set by the U.S. Environmental Protection Agency and the State Water Resources Control Board (State Board). Nitrate levels that exceed the standard have been established as a threat to the public health and subject to regulation.

In 1990, when local corrective action was deemed by the Regional Board to be too slow and inadequate, more formalized enforcement actions were undertaken, resulting in a Prohibition Order that required the abandonment of area septic systems by July of 1995. The issue, which affects over 30,000 residents in the Chico Urban Area, had become increasingly controversial making a timely resolution difficult. The cost of sewering had clearly emerged as a primary concern, especially for those of fixed income and limited ability to absorb the cost. Some doubted the adverse health effects of groundwater nitrate, or the integrity of test results, or dismissed the issue as a ploy to force unincorporated residents to annex to the City of Chico. Since high nitrate levels were first discovered in private wells in 1979, few local issues have held the potential to affect such a large segment of Chico-area residents. The local nitrate problem has spawned numerous studies and regulatory actions, complicated and impacted home sales, worried those on private wells, and generated hours of debate.

1.2 Nitrate Compliance Program

Following previous unsuccessful attempts to resolve the issue and subsequent imposition of the State's Prohibition Order in 1990, Butte County initiated a concerted effort to analyze the problem and develop the most appropriate and cost-effective solution. Largely discounting previous technical studies whose adequacy or accuracy was in question, and utilizing revenue from County Service Area 114 assessments, the county's Nitrate Compliance Program started fresh. Newly emphasized were the elements of communication among citizen's groups generally in opposition, Regional Board staff, and other involved parties.

This document marks the arrival of a key decision point in this important issue. The scientific studies and engineering analyses have now been completed, alternative solutions and strategies developed and considered, and conclusions and recommendations reached. Herein is a report which includes a summary of key studies, a discussion of possible actions, and a recommended program of actions.

It is hoped that this document will assist the public, the agencies, and the decision-makers in their consideration of these matters. A deliberate attempt has been made to prepare a document that would be readable and understandable by the general public. The nature of the subject matter, however, often required the use of technical concepts and terminology. To assist the reader, an extensive glossary of terms is set forth in Appendix A. A list of all references cited in this document is contained in Appendix L.

1.3 Report Purposes and Goals

This document reports the actions taken, and those recommended, to resolve the groundwater nitrate issue in the Chico Urban Area. It is intended to function as a structured response to the Regional Board, an arm of the State Board with jurisdiction in Butte County. Following a period of public review and comment, the implementation portion of the document will be brought back to the Butte County Board of Supervisors and the Regional Board for their approval.

Although useful for official consideration and decision-making, this report is also directed to those who currently rely upon such systems and are directly affected. The Butte County Board of Supervisors has assumed the primary responsibility for responding to the State's requirements on behalf of individual septic system owners. It is the County's goal to effectively communicate with the public and to build a fundamental consensus of support for the proposed actions. Above and beyond the County response to the Regional Board, the need for public awareness and understanding of this complex issue compelled the preparation of a full report, so that property owners and residents could be properly informed.

1.4 Organization of the Report

For those who desire merely an overview, each chapter is headed by a "key points" section. A summary of the findings and conclusions from each of the chapters is presented in Section 1.5. A summary of the proposed Implementation Plan is presented in Section 1.6. Those issues or recommendations of further interest can be examined in more detail within the appropriate chapter.

Chapter One, "Introduction and Summary," consists of an introduction, a brief summary of the report's findings, explanations and recommendations, and a listing of the actions proposed to protect local groundwater quality and to comply with the Regional Board's requirements.

Chapter Two, "Health Effects and Regulation of Nitrate," seeks to provide an understanding of the underlying reasons for concern with nitrate in drinking water and the regulatory response, especially in the Chico Urban Area.

Chapter Three, "Scope and Results of the Technical Program," reports on the technical program, the scientific study and analysis of the hydrogeological, soil chemistry, and other technical aspects of the groundwater nitrate issue.

Chapter Four, "Nitrate Elimination, Reduction, and Onsite Compliance," describes a specific approach to determining the extent of sewering and other actions needed to protect local groundwater, based on the results of the technical program.

Chapter Five, "Sewer Feasibility, Cost and Financing," summarizes a feasibility analysis which examines alternative methods of providing sewer service to those areas for which it is recommended, including preliminary cost estimates for the recommended alternative of connection to the existing collection and treatment system operated by the City of Chico.

Chapter Six, "Oversight Monitoring Program for Onsite Systems," discusses a program to oversee the operation and maintenance of onsite wastewater systems in the Chico Urban Area. For the approximately 4,200 dwelling units recommended to continue using septic systems, public oversight administered by the Butte County Division of Environmental Health is a more cost-effective means to protect groundwater than is sewering. An oversight monitoring program is contemplated to minimize or substitute for sewering, in specified circumstances.

Chapter Seven, "Local Government Jurisdiction, Development and Related Issues," addresses the related issues of land use, new development, and annexation to the City of Chico. Although not complete, the city and county have made substantial progress toward consensus on these issues, and a specific approach is described herein.

Chapter Eight, "Environmental Review and Compliance," discusses a method of compliance with the California Environmental Quality Act (CEQA) via a "project Environmental Impact Report". A project Environmental Impact Report enables the consideration of the overall implementation plan without inappropriate attention to details that are not yet known or timely. A Project Environmental Impact Report is described in Section 8.4.

Chapter Nine, "Implementation Components and Schedule," compiles a list of implementation components and presents a proposed schedule, with emphasis on the actions leading to formal agreement by the County of Butte, Regional Water Quality Control Board and City of Chico.

The Appendices section, starting with an extensive glossary, includes copies of many relevant documents for reference and detail.

1.5 Summary of Findings and Conclusions

                                          (see report at section indicated below)

1. Numerous scientific studies provide a strong basis for the regulation of nitrate in  drinking water. Methemoglobinemia (blue-baby syndrome), possible carcinogenic effects, and other health concerns support the basis for nitrate regulation. The nitrate regulatory level for groundwater contamination in California is 45 mg/l.                                                               2.1

2. Potential sources of nitrate in groundwater include agricultural and domestic fertilizers,  animal waste, septic system effluent, and natural sources.                                                                       2.2

3. Groundwater regulation in California is set forth in the Porter-Cologne Water Quality  Control Act (State Water Code), and is within the purview of the State Water Resources Control Board and Regional Boards. Numerous programs and enforcement measures are available to regulators to ensure the protection of groundwater quality.                                                                2.3

4. The Prohibition Order and other actions by the Regional Board are intended to enforce  the nitrate standard and compel a reduction in total nitrate loading to groundwater.                   2.5

5. In order to definitively establish the scope and extent of nitrate contamination and  provide the technical basis for resolution satisfactory to the regulatory bodies and the public, a comprehensive scientific program has been completed.          3.3

6. The results of the technical program are generally consistent with previous studies, although some differences were found.3.3

7. An evaluation of all potential nitrate sources strongly supports the conclusion that  septic tank discharge is the primary source of groundwater nitrate in the Chico Urban Area.                         3.3

8. A simplified mass balance equation was used to predict the level of wastewater  loading that could be sustained without causing exceedance of the maximum contaminant level. The technical program results now support a relaxation of density limits from one unit per acre to approximately four units per acre.

                                                                                                 3.4
9. The results of the technical program are the scientific basis for the designation of areas that must sewer to eliminate their nitrate discharge to groundwater, and areas where existing onsite systems may continue to operate.                                             4.1

10. The proposed actions are intended to reduce the overall nitrate loading in the Chico Urban Area to a level which will not cause or perpetuate an excessive level ofgroundwater nitrate.  4.1

11. The areas proposed for sewering have an average overall density of approximately  four dwelling units per acre or more, a density which has been demonstrated to exceed the capacity of the soil and receiving waters to assimilate nitrogen. A much smaller set of properties exhibit other characteristics such as high groundwater or other problems that tip the scales to the alternative of sewering.                                                           4.2-3

12. A potential nitrate-reducing system retrofitted to an existing septic system appeared promising and was closely examined, but is not recommended for widespread usedue to low reliability, high maintenance requirements and lack of significant cost savings, although use of these systems can be further explored.          4.4

13. Connection to the City of Chico's existing gravity collection system and sewage treatment plant is the most cost-effective alternative for sewering designated areas.                                5.1

14. The average construction cost per dwelling unit and related city connection fees is estimated to be approximately $6,000 plus an additional $2,000 to $3,000 for onsite connection costs and the abandonment of septic tanks.                                            5.2

15. In the absence of governmental grants, individual residents will bear the burden of paying for sewers through a combination of public and private financing mechanisms intended to allow payment over a 10-20 year period.                                            5.3

16. Building on the proposed implementation plan components set forth herein, further work and consultation with relevant agencies is needed to develop a detailed sewer financing program.

                                                                                                  5.6
17. An oversight monitoring program is necessary to ensure that continued operation of remaining individual onsite systems will protect groundwater quality.                                                      6.2

18. Utilizing CSA 114 is considered the best alternative to fund the oversight monitoring  program.                                            6.2

19. Butte County and the City of Chico have previously cooperated on many issues,  including those related to the nitrate issue. It is imperative that every effort be made to further cooperate on the actions recommended herein.                        7.2                       

20. The County and City are currently negotiating in an attempt to resolve substantial differences regarding annexation to the City of Chico as a condition of sewer services. It is the intent of this plan that sewering to achieve water quality will not involve annexation.                                                                                7.3

21. Informational workshops will be held within the Chico community prior to final  consideration by the Board of Supervisors.                                                                            9.2-3

1.6 Summary of Proposed Plan

22. Public education efforts will assist owners of septic systems in extending the  functional life of their systems and ensuring dis- charge within the parameters of regulatory requirements.       6.3

23. New residential development on septic systems is to be limited to specified areas  with a minimum parcel size of 20,000 square feet equivalent to approximately two dwellings per acre.          7.4

24. Over approximately a seven to ten year period, phased sewer service will be extended to  approximately 7,800 dwelling units within designated subareas, commencing with the area of highest priority and economic feasibility.                                              4.6

25. The mechanisms to finance the sewering program have not all been identified or developed. A combination of loan programs to assist with financing the sewer improvements, with emphasis on the low-interest State Revolving Fund loan program and the use of a special assessment district, will be pursued in coordination with any available grants. Further structuring and refinement of a financing program will be necessary following adoption of the Plan.                                                                                           5.5