Record of Decision for Construction and Operation of the Tertiary Treatment Plant and Associated Facilities at Marine Corps Base Camp Pendleton, California

AGENCY:

Department of the Navy, DOD.

ACTION:

Notice of record of decision.

SUMMARY:

The Department of the Navy (DON), pursuant to section 102(2)(c) of the National Environmental Policy Act (NEPA) and its implementing regulations (40 CFR parts 1500-1508), announces its decision to consolidate four active sewage treatment plants (STPs) at Marine Corps Base (MCB) Camp Pendleton into a single tertiary treatment plant (TTP). This involves construction and operation of a new TTP and associated facilities and demolition of four active and one inactive STP.

ADDRESSES:

A copy of the Environmental Impact Statement (EIS) addressing this decision may be obtained from Commander, Southwest Division, Naval Facilities Engineering Command, Attn: Jill Wellman, Code 5 CPR.JW, 1220 Pacific Highway, San Diego, California 92132-5190.

FOR FURTHER INFORMATION CONTACT:

Ms. Jill Wellman, telephone 619-532-4742.

SUPPLEMENTARY INFORMATION:

The proposed action will construct and operate: The TTP, which will be located near the site of existing STP 13; a conveyance system to transport wastewater from the collection areas of active STPs 1, 2, 3, and 13 to the TTP; and a wastewater reclamation system to store and convey tertiary-treated water to reuse points. The proposed action will also dispose of excess tertiary-treated water via an ocean outfall; demolish active STPs 1, 2, 3, and 13, and inactive STP 8; and relocate the existing recycling center.

Currently, there are five STPs (STPs 1, 2, 3, 8, and 13) located within the southern portion of MCB Camp Pendleton. However, STP 8 is no longer in operation, and a sewage lift station located at inactive STP 8 is used to convey wastewater to STP 3 for treatment. The STPs currently collect and treat wastewater from within the Lower Santa Margarita River Basin. The proposed action will restructure MCB Camp Pendleton's current wastewater treatment system by consolidating active STPs 1, 2, 3, and 13 (which currently provide secondary treatment), construct a new, regional TTP, and maximize reuse of tertiary-treated effluent. Wastewater secondary treatment generally consists of biological treatment processes to reduce organic solids. Tertiary treatment provides further treatment for the removal of constituents not removed by secondary treatment.

The TTP will include: an influent pump station (to collect wastewater from the tributary area of active STP 13); preliminary treatment, secondary treatment, and tertiary treatment facilities; chemical storage and feed systems; utility systems and standby generators; an emergency management system connection; sludge handling facilities; an effluent pump station; and an operation and maintenance building.

The average wastewater flow at the TTP is expected to be 2.71 million gallons per day (mgd). The permitted flow capacity of the TTP will be 3.25 mgd, representing a difference of 0.54 mgd above existing wastewater flows. However, the maximum permitted flow capacity of the TTP will be 3.75 mgd. The proposed TTP has a design capacity to treat 5.0 mgd. The maximum permitted flow capacity is determined via National Pollution Discharge Elimination System permit provisions which require a facility's permit capacity to be only 75 percent of its design capacity.

The TTP wastewater conveyance system will consist of sewage lift stations and pipelines from the collection areas of STPs 1, 2, and 3 and inactive STP 8. In addition, a junction station will be constructed to accept wastewater flow from pump stations 2 and 3 (to allow transition from pressure flow to gravity flow). TTP wastewater conveyance pipelines will utilize existing pipelines where feasible.

TTP effluent will be reused (i.e., reclaimed) and, when necessary, disposed via an existing ocean outfall. It is expected that all of the maximum permitted flow capacity of 3.75 mgd will be used for wastewater reclamation. However, if 100-percent reclamation cannot be achieved at the maximum permitted flow, the excess effluent (a maximum of 0.27 mgd (300 acre feet per year [afy]) during a normal rainfall year and 0.3 mgd (300 afy) evaluated at the historically wettest rainfall year (1978)) will be discharged via an existing ocean outfall.

The wastewater reclamation system will consist of pipelines, pump stations, and related facilities at each of the areas proposed for reuse of reclaimed water. Conveyance pipelines will tie into the existing pipeline infrastructure where possible. At the reuse sites, irrigation systems and associated pipelines will be installed (either underground or aboveground), as necessary to distribute reclaimed water.

In addition to the reclaimed water conveyance system components, two seasonal storage basins will be constructed through expansion of existing ponds to store reclaimed water during months of low irrigation demands (i.e., periods of high rainfall). The 13-acre Lemon Grove percolation ponds are the first of these storage basins. They are currently inactive and available for conversion to seasonal storage basins for wastewater effluent storage. The percolation ponds will be upgraded to storage basins by raising the berm heights, installing synthetic liners (to prevent seepage and protect inner slopes from erosion), and adding algae chemical storage facilities.

The second storage basin is Gooseneck Lake (Pond 2), which currently holds water ponding from natural surface flow. Pond 2 will be expanded to provide seasonal storage for 250 acre-feet of reclaimed water. Pond 2 expansion will require draining the pond, raising the Pond 2 dam height, installing a synthetic liner, realigning a dirt access road surrounding Pond 2, and a petroleum pipeline.

The two seasonal storage basins will store reclaimed water during low irrigation demand months (i.e., winter months) and supplement reclaimed water flow during peak demand months (i.e., summer months). Pipelines will be installed to connect the storage basins with the proposed TTP and the reuse conveyance systems.

Under the proposed action, once construction of the new wastewater and reclaimed water conveyance systems is complete, STPs 1, 2, 3, 8, and 13 will be demolished. After demolition, the sites will be investigated according to the Comprehensive Environmental Response, Compensation, and Liability Act. Eventually, the sites will be returned to a natural state. However, approximately 1-acre at each STP site will be maintained in a developed condition to accommodate a sewage lift station, potential future conveyance system expansion and maintenance.

Construction of the TTP and wastewater and reclamation conveyance systems will consist of a multi-year, phased construction program that will occur over approximately two to seven years (between fiscal years 2004 [FY04] and FY10). Construction of the TTP will begin first (FY04-05), followed by the wastewater and reclamation conveyance systems (FY05-07), and the demolition of STPs (FY09-10). The active STPs will remain in operation until the completion of wastewater and reclamation conveyance system construction.

Alternatives evaluated in the EIS included the proposed action, three action alternatives, and the no action alternative. Alternative 1 contains all project components associated with the proposed action. However, alternative 1 differs from the proposed action in that it includes additional wastewater reuse areas; reverse osmosis treatment of potable water; a wastewater treatment or reuse wetland; live-stream wastewater effluent discharge; and groundwater recharge. Alternative 2 contains all project components associated with the proposed action. However, alternative 2 differs from the proposed action in that it includes additional wastewater reuse areas; a wastewater treatment wetland; live-stream wastewater effluent discharge; and groundwater recharge. Alternative 3 contains all project components associated with the proposed action. However, alternative 3 differs from the proposed action in that it includes additional wastewater reuse areas; potable water and wastewater reverse osmosis treatment; a wastewater reuse wetland; live-stream wastewater effluent discharge; and groundwater recharge. Under the no action alternative, effluent discharges from STPs 1, 2, 3, and 13 will continue through the City of Oceanside's ocean outfall and secondary treated effluent will be discharged to the ocean. Secondary treated effluent from STP 1 and 2 will also be used to irrigate the golf course when necessary.

MCB Camp Pendleton has a utility contract with the City of Oceanside to discharge secondary-treated effluent from MCB Camp Pendleton to the ocean outfall for a period of 5-years (with an additional 3-year option). Under the no action alternative, at the end of the agreement with the City of Oceanside, treated effluent from STPs 1, 2, and 3 may be discharged at the Lemon Grove percolation ponds, and effluent from Sewage Treatment Plant 13 may be discharged into the Twin Lakes percolation ponds, the Lower Santa Margarita River, or the Lemon Grove ponds.

The DON has determined that the proposed action is the environmentally preferred alternative.

The DON prepared an EIS to evaluate the potential impacts associated with implementation of the Proposed Action. The Draft EIS was provided to the public for a 45-day review and in conclusion of that process, two comment letters were received. The California Coastal Commission (CCC) reviewed the EIS and provided a letter of concurrence. The State Historic Preservation Office (SHPO) is finalizing a Memorandum of Agreement, and the U.S. Fish and Wildlife Service (USFWS) provided a Biological Opinion in response to the Biological Assessment. A Final EIS containing the CCC letter of concurrence, the Biological Opinion, and the public comments and responses to public comments received on the Draft EIS was distributed to the public on April 23, 2004, for a 30-day review. No comment letters were received on the Final EIS.

The DON evaluated direct, indirect, and cumulative impacts associated with implementation of the proposed action affecting land use; air quality; geological resources; biological resources; cultural resources; water resources; environmental justice; utilities and infrastructure; and safety and environmental health. Detailed discussion of the impacts is contained in Chapter 4 of the Final EIS.

The proposed action was designed to locate its components, to the maximum extent practicable, in areas without threatened or endangered species or sensitive vegetation types and within previously disturbed areas. For example, much of the wastewater and reclamation conveyance pipeline alignment follows the alignment of existing pipeline. The mitigation measures presented below will be implemented to reduce impacts to below a level of significance (the mitigation acreages presented below for each biological resource are expressed as the maximum number of acres since the project is a design-build project and the specific location or footprint of the project components is currently unknown):

Vegetation Types—permanent, direct impacts to riparian habitats that are not “Waters of the U.S.” will be mitigated through exotic species control at ratios up to 2:1. Temporary, direct impacts to riparian habitats that are not “Waters of the U.S.” will be mitigated through site restoration, monitoring, and exotic species control at ratios up to 2:1. Permanent, direct impacts to coastal sage scrub (CSS) and Disturbed CSS (D-CSS) will be mitigated at 2:1 and 1:1, respectively. Temporary impacts to CSS and D-CSS will be mitigated through revegetation with native CSS in the project areas.

Mitigation Acreages—for riparian vegetation, exotic species control mitigation will be 3.14 acres. Upland habitats replacement mitigation will be 35.55 acres of CSS and D-CSS, and riparian replacement mitigation will be 4.3 acres.

“Waters of the U.S.”—permanent, direct impacts to riparian habitats that are “Waters of the U.S.” or vernal pools will be mitigated through replacement of lost habitat at a ratio of 3:1. Temporary, direct impacts to riparian habitats that are “Waters of the U.S.” will be mitigated through site restoration, monitoring, and exotic species control at ratios up to 2:1.

Mitigation Acreages—exotic species control mitigation will be 3.86 acres. Replacement mitigation will be 11.31 acres.

Sensitive Species—to the maximum extent practicable, construction activities will take place outside the breeding season of the arroyo toad, light-footed clapper rail, least Bell's vireo, southwestern willow flycatcher, and coastal California gnatcatcher, where these species are present. Construction activities within known arroyo toad habitat or in the vicinity of nesting sensitive bird species will be conducted in accordance to USFWS mitigation requirements presented in the Riparian Biological Opinion for MCB Camp Pendleton.

Cultural Resources—the proposed action will adversely affect archeological site CA-SDI-14170, a site determined to be eligible for listing on National Register of Historic Places. Data recovery to mitigate for impacts to the site will be conducted in accordance with a Memorandum of Agreement with the SHPO. As a requirement of the Memorandum of Agreement, a historic properties treatment plan will be prepared and submitted to the State Historic Preservation Office. The plan will include pre-construction trenching in areas where there is a high potential for buried archaeological deposits; data recovery of sites eligible for inclusion in the National Register of Historic Places; a construction monitoring program; and treatment of newly discovered sites. In addition, the plan will address Native American involvement and establish a program for managing inadvertent archeological discoveries cognizable under the Native American Graves Protection and Repatriation Act.

All practicable means to avoid or minimize environmental harm from implementing the proposed action have been considered. Potential impacts to natural and cultural resources will be mitigated to below a level of significance. On the basis of the EIS findings conducted in accordance with the requirements of NEPA, and after careful review of all comments received during the EIS process and the impact analysis performed for the proposed action, I conclude that implementation of the proposed action will not have a significant, unmitigable impact on the human or natural environment.