Record of Decision To Implement the Sewage Effluent Compliance Project for the Las Pulgas and San Mateo Basins of Marine Corps Base, Camp Pendleton, CA

DEPARTMENT OF DEFENSE

Department of the Navy

Record of Decision To Implement the Sewage Effluent Compliance

Project for the Las Pulgas and San Mateo Basins of Marine Corps Base,

Camp Pendleton, CA

Pursuant to Section 102(c) of the National Environmental Policy Act

(NEPA) of 1969, and the Council on Environmental Quality Regulations

(40 CFR parts 1500-1508), the Department of the Navy announces its

decision to upgrade the wastewater treatment and disposal systems in

the Las Pulgas and San Mateo Basins of Marine Corps Base (MCB), Camp

Pendleton, California. Upgrades in the Las Pulgas Basin involve the

construction of advanced wastewater treatment (AWT) facilities, a

pipeline of approximately 19,000 lineal feet, and a field of injection

wells downstream near the coastline. The AWT facilities would provide

limited tertiary treatment of the sewage effluent, which would reduce

the turbidity and pathogens to decrease the likelihood of clogging

during effluent disposal into the injection wells. Upgrades in the San

Mateo Basin involve construction of equalization ponds, a pipeline of

approximately 12,500 lineal feet, and percolation basins approximately

35 acres in total size located downstream of existing potable water

wells. Additionally, a pipeline connector of approximately 5,100 feet

will be constructed to convey to the San Mateo Basin excess sewage

effluent from the pipeline serving sewage treatment plants in the San

Onofre Basin.

The existing sewage treatment plants were constructed in the 1940s

and discharge secondary-treated effluent to percolation basins upstream

of potable water wells that serve developments within the Las Pulgas

and San Mateo Basins. These conditions, including plant design, violate

the San Diego Water Quality Basin Plan, the State of California Porter

Cologne Water Quality Act of 1969, and the National Pollution Discharge

Elimination System requirements of the Federal Water Pollution Control

Act of 1972. As a result of these conditions, the San Diego Regional

Water Quality Control Board issued Cease and Desist Orders to MCB Camp

Pendleton in January 1989. To meet these Cease and Desist Orders, new

facilities are required to improve wastewater treatment and disposal

and meet the Basin Plan.

Alternatives considered for correcting the conditions cited in the

Cease and Desist Orders included no action, water disposal of effluent,

and land disposal of effluent. Water disposal alternatives included

construction of an ocean outfall, live-stream discharge of either

secondary- or tertiary-treated effluent, discharge to an off-base

publicly owned treatment works, and a basin plan amendment. Land

disposal alternatives included percolation basins, biological ponds,

leach fields, and injection wells. The Draft Environmental Impact

Statement (DEIS) identified the following preferred alternatives for

the Las Pulgas and San Mateo Basins, respectively: construction of

eight new injection wells located west of Interstate 5 for discharge of

effluent from sewage treatment plant 9, which will be upgraded with new

AWT facilities to provide additional filtration required to improve

water quality and prevent clogging of the wells; and discharge of

secondary-treated effluent from sewage treatment plant 12 to new

percolation basins located downstream from existing potable water

wells. These alternatives were identified in the Final

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Environmental Impact Statement (FEIS) as the environmentally preferred

alternatives for each respective basin.

A systematic and multidisciplinary approach to identify

alternatives was utilized which incorporated criteria based upon

technical and functional suitability. Alternatives were evaluated for

technical suitability through compatibility with constraints imposed by

available land for treatment and disposal facilities, subsurface

geological and hydrological conditions, and soil permeability.

Technically suitable alternatives were further evaluated for their

ability to satisfy the following six functional requirements of the

projects: (1) Prevention of degradation of water quality to sustain

beneficial uses identified in the San Diego Basin Plan, (2) sustained

volume within each water basin, (3) prevention of saltwater intrusion

into each water basin, (4) compliance with water quality standards in

accordance with Federal and State safe drinking water standards, (5)

compliance with water quality standards in accordance with State

Groundwater Recharge Guidelines, and (6) compliance with the timelines

identified in the Cease and Desist Orders. The analysis determined that

the preferred alternative in each basin is the only alternative that

meets all criteria. In each basin, the preferred alternative is

environmentally preferable to the other alternatives considered because

it sustains long-term water quality and meets the San Diego Basin Plan

objectives. All practicable means to avoid or minimize environmental

harm have been adopted as identified below and amplified in the

Environmental Impact Statement.

For the Las Pulgas facility, construction of the new AWT

facilities, equalization pond, pipeline and injection wells will

require grading, excavation and soil-boring. For the San Mateo

facility, percolation basin construction will involve grading and

excavation. A soil erosion control plan will be prepared for

construction, and will include restricting grading and excavation

during the rainy season, restricting heavy equipment to existing

rights-of-way, installing sediment control measures, and providing

post-construction revegetation.

To reduce potential significant impacts on paleontological

resources to an acceptable level, the Marine Corps will develop an

environmental education program, develop an information pamphlet and

conduct an environmental education class for all construction project

personnel. Additionally, environmental monitors shall be present when

construction activities occur in designated sensitive areas.

Environmental monitors shall ensure that paleontological resources are

recovered according to approved procedures. If paleontological

resources are identified and salvage efforts are required, curation of

the materials will be accomplished by the Marine Corps.

The California gnatcatcher (Polioptilla california), a federally

listed threatened species, is present near the percolation basin and

pipeline sites. The project will result in a temporary impact to 1.35

acres of coastal sage, of which only 0.4 acres are occupied gnatcatcher

habitat. In accordance with USFWS Riparian Biological Opinion (BO) of

1995, to mitigate these impacts, the Marine Corps will, to the maximum

extent possible, conduct construction operations in coastal sage

habitat outside of the gnatcatcher breeding season. Construction that

will occur within 500 feet of coastal sage during the breeding season

will be surveyed prior to construction to determine the presence of

active gnatcatcher nests, and all work within 500 feet of a nest will

be completed outside the breeding season. All pipelines will follow

existing roads to the maximum extent practical. Temporary impacts to

coastal sage will be mitigated through replanting, restoration and

subsequent monitoring of the restoration area for a minimum period of 3

years to ensure restoration success and to control invasive exotic

vegetation. Permanent impacts to coastal sage not occupied by

gnatcatcher shall be mitigated at a ratio of 1:1, and will be

accomplished through habitat enhancement and conservation in the more

contiguous area of coastal sage on the Base. The U.S. Fish and Wildlife

Service (USFWS) concurs with this mitigation scheme.

The southwestern willow flycatcher (Empidonax trailii), a federally

listed threatened species, is known to occur in the riparian areas of

the Las Flores Creek drainage. The project will result in a permanent

loss of 2.28 acres and temporary loss of .07 acres of southern willow

scrub which is potential habitat for the willow flycatcher. The USFWS

Riparian Biological Opinion (BO) of 1995 indicated the impacts would be

significant and require mitigation. As mandated in this BO, permanent

impacts to riparian wetland habitat shall be mitigated at a ratio of

1.5:1 by enhancing degraded habitat elsewhere on- or off-base.

Mitigation will be achieved through implementation of invasive exotic

plant species control, site monitoring, and follow-up retreatment for a

period of 5 years. Temporary impacts to riparian wetland habitat will

be mitigated by restoring wetlands to original or better condition and

by monitoring the restoration for a minimum of 3 years to control

invasive exotic plant species and to ensure restoration effectiveness.

In accordance with the 1995 USFWS Riparian BO, temporary impacts to

estuarine wetland habitats will be restored to original or better

condition following construction, and will be monitored for a minimum

of 3 years to control invasion of invasive exotic plant species to

ensure effectiveness of restoration.

To ensure avoidance of temporary impacts to the southwestern arroyo

toad (Bufo mocroscaphus), construction will be scheduled during the

period between September 15 and January 15, when toads are hibernating

and activity is minimized. For construction that cannot be accomplished

between September 15 and January 15, toad-proof fencing will be

installed daily at all open trenches and soils stock piles.

Additionally, on a daily basis, a biological monitor shall verify the

absence of toads in construction areas prior to the commencement of

construction. These mitigation measures comply with the 1995 USFWS

Riparian BO.

In compliance with the 1995 USFWS Riparian BO, the Marine Corps

will conduct monthly surface water quality monitoring for up to 2 years

to establish baseline data for areas downstream of the percolation

basins. Monitoring data will be collected in accordance with the

provisions of the Clean Water Act Section 404 and 401 permit. Should

changes in water quality be detected, the Marine Corps will consult

with the San Diego Regional Water Quality Control Board (SDRWQCB) and

the USFWS to develop and implement appropriate mitigation measures.

Additionally, the Marine Corps will annually monitor ground water

quality and levels for 10 years, as stated in the 1995 USFWS Riparian

BO. Should changes in ground water quality or level be detected, the

Marine Corps will consult with the SDRWQCB and the USFWS to develop and

implement appropriate mitigation measures.

The proposed action will affect two archeological sites determined

to be eligible for listing on the National Register of Historic Places.

Where feasible, adverse direct and indirect impacts on archeological

resources will be avoided through redesign or relocation of facilities

to avoid areas of high cultural resource sensitivity. In areas where

avoidance is not feasible, the Marine Corps will prepare a data

recovery plan and consult with the California State Historic

Preservation Officer (SHPO) for concurrence prior to

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implementation; provide for monitoring of construction and excavation

operations by a qualified archaeologist and a Native American observer;

and should archaeological resources be encountered during construction,

halt all work until a qualified archaeologist is consulted to determine

if the resources are significant and whether excavation or protection

of resources is required. The California SHPO concurs with this

approach.

Analysis of air emissions that would occur during construction and

operation of the percolation ponds determined that these emissions will

be below de minimis levels and that the project conforms with the State

Implementation Plan for air quality.

A Coastal Consistency Negative Determination was prepared for this

project and it concluded that the proposed action is being carried out

in a manner consistent, to the maximum extent practicable, with the

enforceable policies of the California Coastal Management Plan. The

California Coastal Commission concurs with this determination.

Preparation of the Environmental Impact Statement began with a

public scoping process to identify issues that should be addressed in

the document. Involvement in scoping was offered through a combination

of documented public announcements and meetings with State of

California agencies. Public announcements were handled through scoping

letters sent to Federal, State, and local governmental agencies,

citizen groups and associations, and the general public. Also, a Notice

of Intent to prepare an Environmental Impact Statement was published in

local newspapers and the Federal Register. A public scoping meeting was

held on December 17, 1992 in Oceanside, California.

The Notice of Availability of the DEIS appeared in the Federal

Register on September 6, 1996. The DEIS was distributed to agencies and

officials of Federal, State and local governmental agencies, citizens

groups and associations, public libraries and other interested parties.

The public review period for the DEIS was from September 6, 1996

through October 22, 1996. Comments received on the DEIS focused on

alternatives analysis, endangered species and wetlands issues. The FEIS

addressed these comments and was distributed to officials of Federal,

State and local governmental agencies, citizens groups and

associations, public libraries and to other interested parties on

February 7, 1997. No comments were received on the FEIS.

The Department of the Navy believes that there are no outstanding

issues to be resolved with respect to this project. Questions regarding

the Environmental Impact Statement prepared for this action may be

directed to Mr. Lupe E. Armas, Assistant Chief of Staff, Environmental

Security, Marine Corps Base, Camp Pendleton, CA 92055-5008, telephone

(619) 725-4512.

Dated: April 17, 1997.

Duncan Holaday,

Deputy Assistant Secretary of the Navy, (Installations and Facilities).

[FR Doc. 97-10385 Filed 4-21-97; 8:45 am]

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