5.8(b)(2) Criteria for recognition of zones of saturation. |
(2) | Time for testing. Except for tests in connection with the alteration, without expenses or change in use, or repair of existing systems, where any of the groundwater conditions identified in Sections 5.8(b)(2)(v)(A) or (B) of this article are present, groundwater elevations shall be determined only during the months of January through April (unless the period is lengthened or shortened by NJDEP or by the administrative authority due to a significant departure from normal climatic conditions) and all such tests, whenever conducted, shall be based upon the following: [Amended 6-18-2003 by Ord. No. BH:03-01] |
| i. | Profile pits. Water levels shall be measured directly within soil profile pits. Profile pits shall be dug in natural soil immediately outside of or within a fifteen-foot radius of the proposed disposal system. The profile pits shall be a minimum of 10 feet in depth or to bedrock, but in no case shall the profile pit extend less than eight feet below the bottom of the proposed level of infiltration. |
| ii. | Size of profile pits. The profile pit shall be of such size as to permit ready observation of earth material characteristics, depth to seasonal high water table and depth to bedrock. |
| iii. | Groundwater tests. Groundwater tests shall be conducted to provide evidence of the elevations of the regional zone of saturation. Testing shall not be conducted until initial groundwater stabilization is established over a period of not less than 24 hours from the installation of the test equipment, using a test method to be proposed by the applicant's engineer and witnessed by the administrative authority or its authorized agent. Initial groundwater stabilization shall not be considered reached where the last day's level is higher in elevation than the previous day's. The usual method acceptable to the administrative authority is by piezometers. However, monitoring standpipes, installed vertically within the soil profile pits (after which the pits are backfilled) are allowed. |
| iv. | Initial groundwater stabilization. Groundwater testing shall be conducted after initial (twenty-four-hour) groundwater stabilization is reached. |
| | (A) | Favorable conditions. Where favorable groundwater conditions exist [where none of the adverse criteria listed in Subsections v(A) or (B), below, exist] on the lot (or proposed lot) being tested, the groundwater testing shall be conducted for not less than 24 hours after initial groundwater stabilization. |
| | (B) | Moderate conditions. Where any of the groundwater conditions set forth in Subsection v(A), below, are found to exist anywhere on the lot (or proposed lot), testing shall be conducted for not less than three business days, during the wet season, starting after initial groundwater stabilization. |
| | (C) | Severe conditions. Where any of the groundwater conditions set forth in Subsection v(B), below, are found to exist anywhere on the lot (or proposed lot), testing shall be conducted weekly for eight consecutive weeks during the wet season (normally during the months of January through April). |
| v. | The administrative authority will require monitoring of the water table in addition to the testing described in Subsections i through iv, above, when any of the following conditions are found to exist: |
| | (A) | Moderate conditions. The following groundwater conditions shall require not less than three business days testing, as set forth in Subsection iv(B) above: |
| | | (1) | The groundwater table at any time is observed more than three feet and less than five feet of the surface of the ground; |
| | | (2) | Where there is mottling observed within five feet of the surface of the ground, unless meeting the definition of perched as defined in 7:9A-5.8e.; |
| | | (3) | Where the Hunterdon County Soil Conservation Service, County Soil Survey Report, shows groundwater to be within five feet of the surface of the ground, and the on-site soil profile description matches the description of the soil series in question within the County Soil Survey Report; or the soil is rated as having moderate to severe constraints for septic disposal, as determined by the Soil Conservation Service in its Soil Survey Report, together with a comparison of the soil series present at the site with the soil series description contained in the County Soil Survey Report, shall be provided by the applicant to the administrative authority; or |
| | (B) | Severe conditions. The following groundwater conditions shall require testing weekly during eight consecutive weeks of a wet season, as set forth in Subsection iv(C), above: |
| | | (1) | The groundwater table at any time is observed within three feet of the surface of the ground; |
| | | (2) | Where there is mottling observed within three feet of the surface of the ground, unless clearly and convincingly shown to have been caused by a perched zone of saturation or meeting the definition of perched according to 7:9A-5.8e. |
| | | (3) | Where the Hunterdon County Soil Conservation Service, County Soil Survey Report shows groundwater to be within three feet of the surface of the ground, or shows non-soil to be within three feet of the surface of the ground, and the on-site soil profile description matches the description of the soil series in question within the County Soil Survey Report; or the soil is rated as having "severe" constraints for septic disposal, as determined by the Soil Conservation Service in its Soil Survey Report, together with a comparison of the soil series present at the site with the soil series description contained in the County Soil Survey Report, shall be provided by the applicant to the administrative authority; or |
| | | (4) | Where there is a topographical feature, hydric soils, or hydrophitic vegetation within 100 feet of the test site that would indicate the likelihood of a high seasonal groundwater (less than two feet from the surface of the ground). |
| | | (5) | Where an applicant believes that the period of testing required above should, for good cause, be shortened, and the applicant's engineer has certified that, in his or her professional opinion the results of testing conducted truly and accurately represent the seasonal high groundwater in the area, a request for a variation to shorten the testing period may be made by the applicant and considered by the administrative authority pursuant to the provisions of § 268-19 of this article. |
| | (C) | Testing for moderate or severe conditions shall not be discontinued when the groundwater levels for either of the last two days of testing are higher in elevation than the average daily groundwater levels of the previous days' testing. |
| vi. | In addition to the testing required by Subsections iv and v, above, where the administrative authority has doubt concerning an alleged perched formation or artesian formation, the applicant may be required to perform hydraulic head testing during the months of January through April for a minimum of eight consecutive weeks. This hydraulic head test is to be conducted as prescribed by N.J.A.C. 7:9A-5.9. and read weekly over an eight-week period. |
| vii. | The administrative authority may suspend groundwater testing if it is determined that there has been a significant departure from normal climatic conditions. The administrative authority may monitor the area climatic data, to establish a baseline for the determination of abnormal climatic conditions. |
| viii. | All groundwater test results shall be certified by a licensed professional engineer, and all testing shall be witnessed by a representative of the administrative authority. Reports of the depth to the referenced groundwaters shall be made on forms furnished by the administrative authority. |
| ix. | All test piezometers and standpipes shall be removed within 10 days after completion of the tests and approval of the test results by the Board of Health, except where authorized by the NJDEP for water quality testing. Extensions of time may be granted upon written application to the administrative authority. |