A.1 Introducción: Del briefing a la estrategia

Under this alternative, narrative or numeric water quality objectives would be established to improve water quality for MUN beneficial uses. This alternative is similar to alternative 2 except that the water quality objectives would be more stringent with the intent that water quality would be improved over existing conditions in order to protect MUN uses. Dischargers would be regulated as is described in alternative 2 above, including the potential for a cooperative watershed management approach involving all

affected stakeholders. Should the control measures implemented be sufficient, water quality for drinking water beneficial uses would be expected to improve. However, some constituents of concern for drinking water supplies, specifically organic carbon and nutrients, are necessary for maintaining a healthy ecosystem. Reducing these constituents may impair aquatic life beneficial uses as discussed in the problem statement above. If so, this alternative would be infeasible for these constituents. As water quality improves under alternative 3, public health risk would potentially decrease.

Drinking water suppliers would continue to provide necessary treatment to meet current and potential future regulations.

Climate Change

Climate is defined as expected average conditions, plus the characteristic range of variability of those conditions. Therefore, climate change is the expected difference in the likelihood of types of weather events. The climate system includes the atmosphere, oceans, ice, land, vegetation, and freshwaters. A change in any part of the system can cause global and regional changes to climate. The sun is the energy source that drives the climate system. Greenhouse gases (GHGs) include water vapor, carbon dioxide, methane, nitrous oxides, and human-made chemicals such as chlorofluorocarbons. As these GHGs are emitted into the atmosphere they trap infrared radiation in the atmosphere and cause increases in air, land and water temperatures, also known as global warming.

The United Nations Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two organizations, the World Meteorological Organization and the United Nations Environment Program. The purpose of the IPCC was to evaluate the risk of climate change caused by human activity. Four assessment reports have been completed by the IPCC since its inception. In its Fourth Assessment Report:

Climate Change 2007, the IPCC confirms dramatic changes to our water resources and identifies GHG emissions as the predominant contributor to global warming and resulting regional climate change.

The IPCC’s Fourth Assessment Report presented the Earth’s average temperature data over 140 years. The data showed that since the late 1970s there has been a consistently increasing trend in temperature, about 1.3 degrees Fahrenheit over the 20^th century. This increasing trend has been accelerating faster in more recent years. The IPCC concluded in the Report that within 90 percent certainty the warming over the last 50 years is human induced, attributable to the increased level of GHGs in the atmosphere. The IPCC documented seven global temperature models that estimate the Earth’s average temperature, with the increase ranging from 2.7 to 8.1 degrees Fahrenheit over the next century. Some regional models show temperatures in California increasing as much as 10.8 degrees Fahrenheit.

Since the climate system includes freshwaters, changes to air and land temperatures will have an impact on the timing, amount, type and location of precipitation and runoff in the American River watershed. In fact, the California Department of Water

Resources (DWR) has documented a slight increase in temperature (one degree Fahrenheit) and an increase in annual precipitation (one inch) in the Sacramento River watershed over the 20^th century. DWR research from 1901 to 2000 shows that the Sacramento River system runoff volume has remained stable on an annual basis, but there has been a nine percent reduction in runoff from April through July. This is likely the result of increased winter rainfall and less snowpack storage. DWR also estimate that for each one degree Celsius increase in Earth’s temperature, the Sierra snowpack will retreat 500 feet. This will mean an increase in wet season runoff and less available storage under current operations.

If Earth’s temperature rises, it is expected that water demands would increase and that could result in a longer season of peak treated water demands. It is also possible that increased demands would need to be met through the use of alternate sources, such as recycled water.

On a national level, the USEPA published the National Water Program Strategy:

Response to Climate Change in March 2008. The purpose of this strategy is to provide and overview of the impacts of climate change on water resources and the ability to meet clean water and drinking water standards. In addition, it presented an initial effort to evaluate ways to meet clean water and safe drinking water goals in the context of a changing climate.

x Mitigate GHGs (conservation, treatment, carbon sequestration) x Adaptation of Water Programs to Climate Change

x Climate Change Research Related to Water x Water Program Education on Climate Change x Water Program Management of Climate Change

In June 2005 Governor Schwarzenegger issued Executive Order S-3-05, which established GHG emission targets for 2010 (reduce to 2000 levels), 2020 (reduce to 1990 levels), and 2050 (reduce to 80 percent below 1990 levels). It also required a biennial report on potential climate change effects, including those to water resources, to be prepared by the Governor’s Climate Action Team. In compliance with Executive Order S-3-05, DWR created a Climate Change Technical Advisory Group (TAG). In order to address water resources implications, DWR published a report in July 2006;

Progress on Incorporating Climate Change into Management of California’s Water Resources.

Climate change was identified in the 2005 Update of the California Water Plan (Bulletin 160-05) as a key consideration in planning for the State's future water management.

The 2005 Water Plan update qualitatively described the effects that climate change might have on the State's water supply. It also described efforts that should be taken to quantitatively evaluate climate change effects for the next Water Plan update. The Climate Change TAG is responsible for preparing information for incorporation into the 2009 Water Plan, identifying adaptation strategies for the 2009 Water Plan, and coordinating with the Governor’s Climate Action Team.

Climate change is expected to impact the quantity of water supplies, the management of those quantities, the quality of the source water, and the demand for treated water.

DWR has identified some anticipated changes on the western slope of the Sierra Nevada, these include:

x Increase in temperature (expected to be at least 2.5 degrees Fahrenheit over the next century),

x Slight increase in annual precipitation, with larger and more intense storms resulting in flood conditions, and longer drought periods,

x Decrease in snowpack at lower elevations (DWR projects a 25 to 40 percent reduction in the Sierra snowpack by 2050),

x Earlier timing for spring season runoff, x Increase in evapotranspiration,

x Changes in flora and fauna, and x Increase in forest fire risk.

The preliminary modeling results that DWR has conducted for the Central Valley Project (including Folsom Dam operations) indicates that there would be significant shortages of water in drought years in North of the Delta operations. Current flood control operations would prevent the capture of increased winter runoff and operational changes would be required to avoid shortages. For this reason, it is possible that water management in Northern California could be revised and possible impacts on source water quality include:

x Increase in water temperature,

x Increase in nutrient loading and eutrophication, possibly increases in TOC related to increased algae presence,

x Increase in sediment and pathogen transport and non-point source pollution caused by significant storm events, and

x Increased amount of wastewater/runoff into receiving waters.

Since the impacts of climate change cannot be interceded, water suppliers are being encouraged to begin assessing water supplies and increasing their ability to adapt.

Here are some key thoughts:

x Localized impacts are difficult to predict using current global models and downscaling techniques.

x Demand management through conservation will reduce GHG emissions (comply with Assembly Bill 32) as well limit increases during peak demand periods.

x Water suppliers need maximum flexibility for adaptation in source management (diversification and interconnections) and treatability.

x Water supplies should begin early planning for mitigation (conduct assessments to identify vulnerabilities and potentials).

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The purpose of this section is to (1) evaluate the existing water treatment plants using American River water for their compliance with existing drinking water regulations, and (2) identify potential treatment concerns related to future drinking water regulations.

Appendix B contains a summary of the data provided by each of the participating water utilities, including data sources, water treatment plant summaries, and supporting water quality data. Appendix C provides the Regulatory Framework used as the basis for evaluation.

There are eight existing intakes and 12 existing water treatment plants within the watershed that are included in this study. Each of these is discussed herein within the context of selected current and future regulatory compliance and potential treatment issues beginning with the most upstream diversion point and then moving downstream for each participating water utility.

For assistance with abbreviations and acronyms, the reader is referred to the List of Abbreviations at the front of the Report.

Highlights of Selected Existing Drinking Water Regulations

NIPDWR and Phase I, II, and V Regulations. Set Maximum Contaminant Levels (MCLs) for many inorganic chemicals, synthetic organic compounds (SOCs), and volatile organic compounds (VOCs).

Surface Water Treatment Rule (SWTR). Sets minimum 3/4-log reduction requirement for Giardia and viruses, respectively. Set turbidity requirements, which have since been tightened by the Interim Enhanced Surface Water Treatment Rule.

Interim Enhanced SWTR (IESWTR), Long Term 1 ESWTR and Filter Backwash Rule. Sets minimum 2-log reduction requirement for Cryptosporidium. Requires continuous monitoring of individual filter effluents (IFE) and combined filter effluent (CFE). Tightened treated water turbidity requirements: CFE <

0.3 NTU in 95 percent of monthly measurements, and not to exceed 1 nephelometric turbidity unit (NTU).

Requires recycling of all return flows to the headworks, upstream of chemical feed.

Stage 1 Disinfectants/Disinfection By-Product (D/DBP) Rule. Sets a treatment technology for DBP precursor removal (enhanced coagulation) based on source water total organic carbon (TOC) levels.

Varying levels of removal are required if the source water concentrations are > 2 mg/L. Sets MCLs for total trihalomethanes (TTHMs) and haloacetic acids (HAA5) at 80 and 60 g/L, respectively, in the distribution system as system-wide running annual average (RAA).

Long Term 2 Enhanced SWTR. Requires Cryptosporidium, or Escherichia coli (E. coli) source water monitoring depending on system size. Source water bin classification to be dependent on monitoring results. If running annual average Cryptosporidium value is > 0.075 oocysts/L, bin classification will require additional action (which could be additional log reductions or other actions, including source water protection). Also requires disinfection profiling and benchmarking if system plans to make a significant change to disinfection. A second round of source water monitoring is required, six years after initial bin classification.

Stage 2 D/DBP Rule. Requires compliance with distribution system MCLs for TTHM and HAA5 to be based on locational running annual average (LRAA). Under Stage 2, compliance is based on LRAA of 80 and 60 g/L. Initial Distribution System Evaluations (IDSE) must be completed to identify long term routine monitoring locations. Compliance schedules will depend on system size and source type. For combined distributions systems, all systems will be on schedule of earliest system.

P^LACER C^OUNTY W^ATERA^GENCY(PCWA)