ER IN THE
GROUND WATER IN THE
GROUND WATER IN THE
GROUND WATER IN THE
RARITAN RIVER BASIN
RARITAN RIVER BASIN
RARITAN RIVER BASIN
RARITAN RIVER BASIN
A Technical Report for the Raritan Basin
Watershed Management Project











New Jersey Water Supply Authority
Final Report: June 2002


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GROUND WATER OF THE
RARITAN RIVER BASIN
TABLE OF CONTENTS
ACKNOWLEDGEMENTS........................................................................................................................................VII

SUMMARY................................................................................................................................................................... 1

Ground Water Recharge..............................................................................................................................................................1

Ground Water Contamination....................................................................................................................................................2

Septic System Capacity.................................................................................................................................................................2

HYDROLOGY.............................................................................................................................................................. 3

Definition of Ground Water.........................................................................................................................................................3

Concepts of Ground Water Flow and Recharge.......................................................................................................................3

Hydrology, Topography and Geography...................................................................................................................................4

Water Table vs. Confined Aquifer..............................................................................................................................................5

Karst ................................................................................................................................................................................................6

Basalt/Diabase................................................................................................................................................................................6

Age of Ground Water ...............................................................................................................................................................6

RECHARGE AND USES............................................................................................................................................ 7

Definition of Recharge ..................................................................................................................................................................7

Ground Water Recharge in the Raritan Basin .........................................................................................................................7

Simulation of Ground Water Flows..........................................................................................................................................10

Adverse Effects of Impervious Cover and Soil Compaction Relative to Ground Water Recharge...............................12

Occurrences of Drought in the Basin........................................................................................................................................12

Ground Water Withdrawals......................................................................................................................................................13

Ground Water Discharges .........................................................................................................................................................13

PUBLIC USES...........................................................................................................................................................14

Wells of the Basin.........................................................................................................................................................................14

Wellhead Protection Areas.........................................................................................................................................................14

WATER QUALITY.....................................................................................................................................................16

Causes of Ground Water Contamination and Effects of Land Use on Ground Water Quality ....................................16

Known Contaminated Sites........................................................................................................................................................18

Contaminated Wells....................................................................................................................................................................19

Facilities Handling Solid Waste and Hazardous Materials...................................................................................................20


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ESTIMATING CARRYING CAPACITY FOR SEPTIC SYSTEMS........................................................................22

Geographic Area and Sub-areas ...............................................................................................................................................23

Purpose of Carrying Capacity Analysis...................................................................................................................................23

Assumption Initial Nitrate Concentration in Ground Water............................................................................................23

Target Nitrate Concentration In Ground Water....................................................................................................................24

Assumption Flow and Nitrate Loadings from Septic System............................................................................................25

Assumption Nitrates from Other Sources ............................................................................................................................25

Approach to Estimating Ground Water Recharge ................................................................................................................25

General Limitations to Use of the Model .................................................................................................................................25

Limitations to Use of the Raritan Project Results ..................................................................................................................27

Results of the Septic System Carrying Capacity Analysis.....................................................................................................27

Comparison to Existing Septic Systems ...................................................................................................................................28

MANAGEMENT CONCLUSIONS OF EXISTING PLANS ....................................................................................28

Existing and Proposed Regulations...........................................................................................................................................29

NJ State Development and Redevelopment Plan....................................................................................................................29

1989 Ground Water Strategy.....................................................................................................................................................30

NJDEP Wellhead Protection Program Plan ...........................................................................................................................30

South Branch Watershed Association Wellhead Protection Plan........................................................................................30

New Jersey Statewide Water Supply Plan...............................................................................................................................31

NJDEP Site Remediation Plan ..................................................................................................................................................31

CRITICAL NEEDS ....................................................................................................................................................31

CONCLUSIONS ........................................................................................................................................................32

GLOSSARY OF TERMS ..........................................................................................................................................33

COMMON ACRONYMS...........................................................................................................................................34

REFERENCES ..........................................................................................................................................................34



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LIST OF TABLES
Table 1 Wellhead Protection Areas (WHPA) by Watershed Management Area (WMA)15

Table 2