Friday, June 6, 2008

Protecting Water Quality? Depends where you use it

A discussion of water quality is never simple because water is an essential element for every living system on earth.

Humans have a unique set of perspectives on all these systems, as we are both the observer and the observed. We are integrally woven into the fabric of earth's ecosystems, while constantly trying to understand and/or control the natural environment to better suit the human condition, which has been in an overall state of increasing population for the last three thousand years.

To keep ourselves in balance with nature and each other, we develop rules of behavior called laws, which ideally uses our collective consciousness, to protect our life-giving resources, like WATER.

These rules are written differently, depending on where "our" water is being placed or consumed.

The following was written upon a request by another history editor for the Santa Clara Valley Water Districts second edition of its history book.

Students of environmental studies, including engineers and lawyers, will note that the processes employed to get these laws into our culture took great thinkers and dedicated activists to overcome great ignorance and social inertia.

This process is open ended, so our work is never done, but a snapshot of what we have accomplished to protect water is published below for your consideration:

Santa Clara Valley Water District History in Protecting WATER Quality

Water Quality Concerns Depend Upon Use or Receiving Body.

The following paragraphs describe how water quality is addressed for each body, starting with whole watershed, followed by the groundwater basin due to its enormous value to the SCVWD. The last two bodies are the human community, at large, with its commerce and residential demands, and finally, the human body, and the complex business of protecting public health.

Streams and Bays that receive stormwater and sewage discharges must maintain quality that protects beneficial uses, which are many. If any use cannot be maintained due to discharge of specific contaminant, this becomes a pollution issue that falls within Clean Water Act Federal legislation (dating back to 1972) or the State Porter Cologne Act, that formed the Regional Water Quality Control Boards, which are charged with protecting each of the major watersheds and water bodies in California. The CA Environmental Quality Act (CEQA) and National Environmental Policy Act (NEPA) were both passed with the intention of mitigating negative impacts on air, land and water of proposed or ongoing human activities. The Endangered Species Act also protects water quality when pollution or habitat disruption occurs from a discharge. (the "official" legal mechanism for requiring the implementation of South Bay Water Recycling system)

The SCVWD's engagement in the process of understanding and advocating protection of the water quality of the environment has been occurring on an ever-increasing scale. The District long expressed an interest in protecting the quality of the groundwater basins that can produce upwards of 200 million gallons per day from local wells. Since some portions of the streams in the valley can recharge the aquifers, water quality of the streams has always been a concern of the District.

When the state of California declared the SCVWD to be a stormwater discharger under the Clean Water Act, the District's concern for the quality of the water in storm sewer outfalls became a legal mandate. The District became the first manager of the Santa Clara Valley Urban Runoff Pollution Prevention Program, which is issued a joint NPDES permit through the SFRWQCB. The co-permitees include the District, the thirteen cities and the unincorporated portions of Santa Clara County, which drains to San Francisco Bay.

This gave SCVWD its first direct concern for Bay water quality, and the human impacts on that receiving water body. While the cities operated the sewage treatment plants, the District did not have any legal mandates to protect the quality of the Bay from stormwater discharges until becoming a co-permitees under the basinís urban runoff NPDES.

The District also created a position of Water Quality Manager and hired the former executive officer of the SFRWQCB to fill the position. Soon, the storm drains throughout the County were being stenciled with messages, in multiple languages: "No dumping, Flows to Bay" plus symbols of a fish and water. We were beginning to educate the community about the need to protect the water quality of the streams and understand what a watershed means. Renewed stencils included a message naming the creek or river to which the drain flowed. In 1993, the USEPA gave the SCVWD a special Award of Excellence for its progress on stormwater programs.

In November 2000, the District took the bold step to place before the voters of Santa Clara County a parcel tax to fund the Clean, Safe Creeks and Natural Flood Protection Program. The measure was approved by the required 67% of the electorate. The District subsequently had its mission revised in its enabling legislation to declare it as the official steward of the local watersheds within Santa Clara County. This role continues to evolve as the District becomes more involved with stormwater detention and treatment devices now required of new and redevelopment projects through mandates in the Urban Stormwater permit. The District linkage to land use decisions is necessarily growing stronger, requiring the District to educate and engage all communities' decision-makers about the water quality impacts of hardening the watershed with urban development.

The SCVWD was formed in 1929 to finance and build a water storage and recharge system to augment the yield of the local groundwater basins. A large portion of the basin's well production was originally used for agriculture irrigation, leading to the county being known as the Valley of Heart's Delight. Quality concerns for agriculture were limited to the amount of dissolved salts, with special concerns about sodium, chlorides, and boron.

The groundwater basin itself was designed by nature in such a way that water quality in the aquifers was protected. Natural filtration occurred as water was recharged into the basin through streambeds. The natural recharge capacity was expanded as percolation ponds were created by the District to recharge water in the dry summer months that was captured and stored in the District's 10 reservoirs during rainfall periods. These ponds were located in areas where the gravel lenses of the aquifer intersected with the surface of the valley floor. By developing this land for recharge, the District was unintentionally preventing other possible land uses from occurring on that land which could have caused serious pollution of the groundwater.

Large, thick alluvial deposits of clay on much of the surface of the valley, acted as an aquitard to prevent pollution from migrating vertically downward into the aquifers that were being tapped for the communities' water supply. However, new chemicals would be created over time that could migrate through the clay cap and begin to foul the water quality. The District's response was to form a special unit to track and enforce remediation of contamination plumes, usually occurring due to Leaking Underground Storage Tanks (LUST). Both industrial volatile organic solvents and fuel leaks were discovered at literally thousands of sites throughout the valley.

Responsible parties at major leaks pumped, treated and dumped tens of thousands of acre-feet of contaminated groundwater from plumes and mostly discharged the water to local streams and, ultimately, the bay. Some of the solvents, being volatile organics, transferred to the air from the pumped water as it moved through storm drains, and was fairly clean again when it reached the streams. This pumping occurred for nearly a decade, creating summer flows in some reaches of streams that had not occurred since pre-European occupation of the valley. In some situations, anadramous fisheries reestablished themselves, such as the salmon and rainbow trout now flourishing in the Guadalupe River. Unfortunately, the legacy of mercury mining in that watershed continues to contaminate the fish to levels, which require posting health warnings on eating fish from this watershed's streams.

The ever-increasing demand for pumping of the groundwater basin resulted in extended periods of overdrafting of the basin, which caused the clay deposits to dewater, once artesian pressure was removed from the gravel aquifer lenses. Land surface subsidence began to occur when this condition was sustained over several years. This occurred in the 1920's& 30's and again in the 1950's & early 60's. The response to this water problem was to build two aqueducts from the southern Sacramento-San Joaquin Valley to increase the available water supply for the County, one connected from the State Water Project in 1965 and a second from the Federal Central Valley Project in 1987. Some of this water was, and is still, used to recharge the accumulated overdraft of the groundwater basin. The quality of the imported Delta water was inferior to that captured in local reservoirs, but was close to the ambient quality of the groundwater basins, in all but the driest of years. Delta water has considerable concentrations of salts and pesticides, which require end-of -pipe mitigation at the District's three water treatment plants. The District does not treat Delta water before it is diverted to its percolation ponds, relying on the filtration capability of the basin to remove pollutants before the water reaches an active well.

As the primary business of the valley evolved from agriculture to defense during and after WWII, to today's electronic information components base, the human population has grown steadily, whereas the municipal and industrial demand now constitutes over 90% of the water needs of the SCVWD.

Less than 10% of this amount of water is used toady directly by business, and in many cases, is treated further at the point of use, making the world's cleanest water to use for rinsing silicon-based miniature circuits, called microchips, as well as many other components manufactured in the valley. This ultra pure water, being a safer solvent than the previously used organic solvents, was developed after the near disastrous discharge of previously used solvents from Leaking Underground Storage Tanks (LUST). (These chemicals were also ozone-depleting compounds and would soon by banned by international treaty.)

Water quality protection during the groundwater cleanup phase became a matter of defining "How clean is clean?" and determining how long to operate remediation systems to clean the pumped contaminated waters in the underground plumes. Federal, state and local perspectives and the scientists often disagreed with definitions of risk assessments, or whether that was the even the right approach to the problem. Trying to translate exposure to human health problems and then to translate that assumption to economic values makes the conversation transcend the outer realms of public policy.

In 1990, Congress passed the national Pollution Prevention Act to help reduce the overall problem of linear systems that assumed a waste component on most human activities. By advocating life-cycle analysis, all aspects of a product or service are examined on a cradle-to-cradle basis, and systems are considered to be cyclical, not linear, by nature.

Protection of water quality has now shifted locally to focusing more on pollution prevention. When the cities' were sued in the early 1990's under the Clean Water Act for discharging excess metals to San Francisco Bay, the consent decree included establishing an organization to discuss policies and actions needed to reduce or eliminate pollution at its source. In 1994, the Silicon Valley Pollution Prevention Center (SVP2Center) was formed as a public benefit corporation to serve as the forum for all sectors of the community to conduct its dialogue about pollution sources and create plans for action.

The SCVWD supported this evolution in water quality protection whole-heartedly. District CEO, Stan Williams, served for 6 years as Board President of the newly formed SVP2Center. Pat Ferraro left his elected position on the SCVWD Board in 1995 to accept the position of Executive Director of the SVP2Center. The SCVWD Board appoints two government directors and two business directors to the SVP2Center Board, matching the City of San Jose Council appointments. The SVP2 Center serves as an important link between the SCVWD and the City of San Jose, its largest customer, as well as the other cities, the County of Santa Clara and the business and environmental sectors. Funding for the Center has historically come from San Jose, the SCVWD, and grants and sponsorships from foundations, state government, and corporations. SCVWD also partially funds the County Pollution Prevention Program and the Santa Clara Valley Urban Runoff Pollution Prevention Program.

Body #4: The HUMAN BODY:
The quality of drinking water that is provided by the SCVWD must meet drinking water standards that are established by the Federal Safe Drinking Water Act, and regulated by the State Department of Health Services and the US EPA. The sources of water managed by the SCVWD include local runoff stored in 10 local reservoirs and imported water from two aqueducts which draw water from the western, downstream edge of the Sacramento-San Joaquin River Delta through massive pumping plants located near Tracy.

For emergency situations, the SCVWD has interties to the San Francisco Water Departmentís Hetch Hetchy aqueducts that convey high quality water from a reservoir built in Yosemite National Park. Seven cities that front on the Bay front also contract directly with San Francisco to purchase this high quality water for municipal uses.

The SCVWD's water supplies are delivered to water users either through wells that draw recharged water from the underground aquifers or through deliveries by pipelines from three water treatment plants located in the higher elevations surrounding the northern part of the valley.

Water quality is generally improved by passing through layers of gravel and sand as it percolates down into the groundwater aquifers. The underground basin then serves as both a transmission and relatively safe storage reservoir for the water until it is pumped from wells. Some wellhead treatment, usually chlorination, is performed before water is delivered by the municipal and investor-owned water utilities to homes, businesses and other urban demands.

Water imported by the SCVWD from the Delta is usually of lower quality than either local runoff captured in local reservoirs or the Hetch Hetchy supply. Most of this water is treated in the District's three water treatment plants, although some is also co-mingled, without treatment, and percolated into the local groundwater basins.

The treatment plants must produce water that meets or exceeds water quality standards for many chemical constituents. The standard design for these treatment systems is coagulation, followed by filtration, followed by disinfection. Coagulation is a physical-chemical process that helps fine suspended materials to clump together to either settle out or become large enough to be removed in the next step. Filtration occurs by passing the coagulated water through multi-media bed of sand, gravel, and anthracite coal. The water is then disinfected to eliminate living pathogens. Some is stored in terminal reservoirs and then, eventually, delivered to the water retailers that convey it to the users in the communities.

Chlorine was the primary chemical used for disinfection for many years. In recent years, the SCVWD has used a combination of chlorine and ammonia as a disinfection agent to reduce the level of carcinogenic disinfection byproducts that were formed when chlorine combined with organics present in Delta water. The District is currently modifying all its treatment plants to generate ozone onsite for use in disinfecting water in the plant. A residual amount of chlorine will continue to be added as water enters the distribution system to protect the water from possible regrowth of pathogens.

The science behind the water quality standards that must be met by the SCVWD is often behind the chemical industry's ability to develop and introduce new constituents into the water environment. While some 80,000 known chemicals exist which have the potential to affect the human body, especially during early growth and development, standards exists for less than 100 chemicals. Some of these standards are increased (requiring lower concentrations) as science continues to study human exposure to these regulated chemicals.

Recently, the problem of exposure to Endocrine Disrupting Chemicals (EDC's) was put forth as a potential negative health impact from the proposed use of recycled water to cool a new 600 MW power plant located near some of the Districtís percolation ponds. The first realization was that these chemicals can and do now enter all the Districtís supplies, including the local wastewater that is now being recycled after advanced treatment.

The response to the EDC concern initiated a collaborative workgroup being formed under the Watershed Management Initiative (WMI) to create information to help educate decision-makers and the general public about the sources, potential impacts and pollution prevention initiatives that will reduce exposure and environmental dispersal of some of the more common EDC's.

Increased future use of recycled water will be inevitable in Santa Clara County. As both SCVWD and the SF Hetch Hetchy water systems are renovated to produce safe and reliable supplies of water, local recycling systems will economically be competitive for both nonpotable uses, and possibly, for indirect potable use, after final treatment and removal of all residual constituents. This ultra pure water, like that created by local manufacturers for product rinsing, would be blended to improve reservoir or Delta supplies before recharging theses waters into the groundwater basin.

The protection of human health continues to be a primary role of Santa Clara Valley Water District. Inherent in that role is bringing along their 2 million business and residential users to understand how this concern translates to cost-effective protection of water quality and knowing that all these efforts do protect human health for all sectors of the community.

Version 1.0(4/20/03)
Submitted by:
Patrick T. Ferraro, Executive Director
The Silicon Valley Pollution Prevention Center

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