Early SNMP Case S Early SNMP Case Studies udies Salt and - - PowerPoint PPT Presentation

Early SNMP Case S Early SNMP Case Studies – udies – Salt and Nutrient Management Plans and Salt and Nutrient Management Plans and Relat lated Issues at d Issues at Camp P Camp Pendleton MCB ndleton MCB

Rob Beggs, Brown and Caldwell

November 7, 2013

Water Sustainability for Camp Pendleton

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Camp Pendleton Groundwater Basins

Southern Water System

 Las Flores Basin

‐‐ 1,400 acres

 Santa Margarita

River Basin ‐‐ 4,500 acres Northern Water System

 San Mateo Basin

‐‐ 3,000 acres

 San Onofre Basin

‐‐ 1,200 acres

• 99% of the Base’s water is
• btained from local aquifers

– Supplies 41,000 military and family members on‐base + 60,000 commuters

• Landscape Irrigation (Recreational Fields)
• Base Housing and Bachelor Enlisted Quarters
• Wash Racks
• Indirect Potable Reuse – Groundwater Recharge
• Agriculture
• Salt Water Intrusion Barrier
• Live Stream Discharge
• Supply to Off‐Base Entities

Recycled Water – Future Opportunities

• High TDS in raw

water/Groundwater

• High TDS and nutrients

in recycled water

• Stringent Basin Plan

Objectives

• Pick up of TDS and

nutrients in the collection system

• Challenging Regulatory

Environment

South Base SNMP - Recycled Water Limitations

Numerical Water Quality Objectives for the Ysidora Hydrologic Area Constituent Groundwater Effluent Quality Total Dissolved Solids 750 1054 Chloride 300 324 Nitrate (as N) 2.3 4.5

Groundwater Modeling

SOURCES + Subflow Above Diversion Streambed Infiltration

River, Tributaries Lake Releases, Ditches

Recharge Pond Infiltration Areal Precipitation SINKS – Lower Ysidora Narrows Subflow Groundwater Discharge to Stream Groundwater Pumping Evapotranspiration (NO3‐N) Net Change of TDS / Na / Cl / NO3‐N Mass

• New uses of

recycled water inside and outside

• f LSMR

Basin. Recycled Water Model Inputs

Groundwater Modeling Results

South Base SNMP Results

Table ES-10. Results and Considerations for Potential Future Management Strategies

Management Strategy Advantages Disadvantages Obstacles and Constraints

Advanced Water Treatment Plant

• Improved quality for users
• Reduces salts in wastewater
• Enhances feasibility of other

measures

• High cost
• Energy usage
• Few remaining – proceeding

to construction Salt Source Reductions

• Reduces salts in wastewater

and recycled water

• Need base order

Recycled Water Irrigation • Reduces potable water demands

• Additional regulatory approval

if Basin Plan objectives and Recycled Water Policy guidelines are exceeded Salt Water Intrusion Barrier

• Protects Lower Ysidora
• Reduces effluent outfall flows
• Localized groundwater quality

effects

• New wells needed to fully

utilize protected subbasin

• Additional regulatory approval

to locally exceed Basin Plan

• bjectives

Operational Changes

• Significant groundwater

quality improvement

• Moderate capital costs
• Higher operational costs
• Higher drought risks – less

water in storage

• Pilot testing
• Additional management

facilities Upstream Reductions

• Potentially substantial

groundwater quality improvement

• In-stream benefits
• Actions taken at sources
• Administratively more

complex

• Depends upon actions by
• utside parties – upstream

agencies, Regional Board, etc.

• Associated with antidegradation analysis or a

Basin Plan amendment

• For possible future recycled water projects with

TDS exceeding 750 mg/L, a Maximum Benefit Analysis showed several benefits and no significant constraints.

• A key consideration for the salt water intrusion

barrier project: no downgradient users

• Analysis Results – Benefits greatly outweigh

constraints

South Base SNMP – Maximum Benefit Analysis

• Study and Pilot Test to Inject Recycled Water – Completed
• Recycled Water Master Plan – Completed
• Base Order to Discontinue water softeners – to be prepared
• Off‐ Base Stakeholders’ Workshop
• Advanced Water Treatment Plant – Fall 2012 completion
• Fallbrook PUD SNMP Supplement
• IPR Study
• North Base SNMP

Associated and Follow-on Steps

Feasibility Study – Indirect Potable Reuse

(draft stage)

• Marine Corps Base Camp Pendleton
• September 25 | 2013

Brown and Caldwell

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Projects Location

Example of Evaluation - Percolation Recharge at Rehabilitated Pond

Brown and Caldwell

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Capacity Modeling

– LSMR MODFLOW model was used with particle tracking – Max percolation capacity is 2060 AFY to avoid potential FAT requirement – SMR water diverted to Percolation Ponds may qualify as the diluent water (RWC of 20%) – Percolation for 8 months‐June to January – 1 year retention time to the closest well downstream

Planning Level Project Costs for the Feasible Projects

Brown and Caldwell

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Projects that provide disposal capacity Projects that provide disposal capacity and additional water supply

Northern Basins Salt and Nutrient Management Plan

(in progress)

Northern SNMP - Calibration Run for TDS

Calibration Model Run: NO3-N

Overall Conclusions

SNMPs can be part of the core planning process for:

• More fully utilizing basin capacity
• Recycled water projects
• IPR projects
• Measures to improve groundwater quality
• Showing the value of upstream improvements to

downstream beneficial uses

• Laying out a good pathway for the regulatory

approval process

Questions ????