Article XIVA Groundwater Sustainability Protection

In the event that the preliminary hydrogeologic evaluation indicates that a surface water and/or groundwater divide separates the lot in question, a groundwater pump test will be required for each side of the divide.

The pump test(s) must be conducted at the location(s) most representative of site geologic conditions and locations most effective for evaluating the potential impacts to proximate users of the groundwater resource. Location of Class 1 wells shall also take into consideration convenience of location to proposed improvements. All wells shall comply with PaDEP/BCHD isolation requirements. The applicant's decision shall be reviewed by the Township as part of its review of the applicant's application materials. If it is not possible to meet objectives, then the applicant shall choose a location(s) to optimize location, subject to Township approval.

Section 234-114 of this article outlines the requirements and procedures for notification of owners of existing wells and other groundwater sources (e.g., springs) within the neighbor notification distance. Inadequate notification will require the pump test to be repeated after new notice.

Hydraulic fracturing (aka hydrofracking, hydrofracting).

Any applicant proposing to use hydraulic fracturing or a similar means to increase the yield of any well must notify the Township in advance.

All relevant state, BCHD, DRBC, and/or federal permits for the use of hydraulic fracturing or other means being used to increase the well's yield must also be presented to the Township.

The applicant must also measure the amount of water put into the well to increase the well's yield, and provide that information in its post-test report along with a comparison to the amount of water removed from the well. Any water put into the well must be potable, unless otherwise approved by the Township.

The applicant must also, prior to commencing the pump test, remove the volume of water or other substance put into the well to increase the well's yield and allow the well to stabilize for 24 hours.

(5)

Precipitation.

No required phase of the pump test shall be conducted during a precipitation event or events in which total precipitation equals or exceeds 0.5 inch, or when any of the aforementioned precipitation events are forecast. With the exception of the following, a violation of this provision will require repeating the required phases of the pump test:

If the length of the required phases of the pump test, when considered together, exceeds three days, precipitation exceeding 0.5 inch per day after the third day will not result in failure of the pump test as a whole. However, the applicant's analysis must factor in the potential groundwater recharge from precipitation.

If over 0.5 inch of precipitation occurs during the recovery phase, the applicant must either repeat the pump test beginning after a reasonable assessment phase, or provide precipitation amounts and technical documentation to show that the precipitation did not recharge the aquifer during the recovery and impair the test results. The requirement to repeat the test shall be at the Township's discretion if adequate documentation is not provided to verify that the test results were not impaired by precipitation. The extended monitoring phase shall be exempt from this requirement. For applicants required to undertake extended monitoring, each applicant shall monitor precipitation amounts and provide such data as part of its final analysis.

Precipitation must be recorded with a National Weather Service acceptable rain gauge on site during all phases of testing and measurements for each day must be included in the hydrogeologic report.

Precipitation shall include both snowfall and snowmelt.

(6)

Any pump test that must be repeated, restarted, or reconducted at a reduced demand must satisfy all the requirements of this article.

(7)

It is the applicant's responsibility to collect sufficient data to determine hydrogeologic conditions and to ensure that any exogenous influences can be fully characterized, such as barometric pressure changes or off-site pumping. Barometric measurements and additional water-level measurements can be made by the applicant to evaluate the change in water levels resulting from barometric pressure changes and/or influences from off-site pumping. If an applicant has insufficient data to assess these influences, it must repeat all required phases of the pump test. The earlier failure(s) will be taken into account during application review.

(8)

During all required phases of the pump test, water must not be withdrawn from any observation well installed by the applicant. All testing must be repeated if there are insufficient observation wells as per this article or if an observation well installed by the applicant is pumped during any required phase of the pump test.

(9)

For neighboring wells that have been volunteered for observation, the well need not be fully shut down, including pump turned off, for the duration of required pump testing phases. However, lack of use is preferred. If neighboring volunteered observation wells are not fully shut down for any or all required phases of the pump test, the applicant shall obtain available drawdown data from the volunteered observation wells, to differentiate neighboring observation well usage from the impacts of the applicant's testing.

(10)

Depth-to-water measurements shall be made at the beginning and end of each pump testing phase.

(11)

General recording and equipment requirements.

Test well(s).

Measuring equipment.

[a]

A calibrated meter(s) must be used to accurately measure the total volume of water pumped from the test well(s) and provide a digital reading of the flow rate. The total meter reading must be recorded prior to the start of peak demand phase, at the end of the peak demand phase, and at the end of the constant head phase. Calibration certificates for the meter(s) must be submitted with the final report. If the meter(s) has not been calibrated within one year of the testing date, the pump test must be repeated.

[b]

Calibrated loggers must be used to monitor the water level in the test well(s) throughout all phases of the pump test. Calibration certificates for the meter(s) must be submitted with the final report. If the meter(s) has not been calibrated within one year of the testing date, the pump test must be repeated.

Pumping equipment. All pumping equipment must have sufficient check valves to prevent backflow into the well from the water in the piping once the pump is shut down. If water drains back into the well from the piping, the test will be deemed to have failed and all required components of the pump test must be repeated.

Observation wells. Observation wells shall be required to use a calibrated logger to measure water-level drawdown during the pump test and for the calculation of aquifer hydraulic characteristics. Calibration certificates for the meter(s) must be submitted with the final report. If the meter(s) has not been calibrated within one year of the testing date, the pump test must be repeated.

(12)

General data monitoring requirements. All test and observation well(s) shall be monitored to determine and evaluate water-level drawdown, calculate aquifer characteristics, determine the radius of influence, determine added drawdown in observation wells, and predict and/or observe the effect of long-term pumping in the test well(s) on water levels in existing and future wells.

(13)

General pumping requirements.

If the flow rate varies by more than 10%, the entire test shall be repeated. The initial failure(s) will be taken into account during application review.

If the pump shuts down during any pumping phase, the entire test must be repeated. The test must be restarted at the beginning of the baseline assessment phase.

If water levels in the test well and/or observation wells exceed the measurement capacity of the devices used for measuring changes in water levels and measurements are not recorded with other devices in accordance with the requirements of this article, the test must be repeated.

If the pumping data indicate a change in aquifer transmissivity as a result of fracture dewatering, all analyses of the contributing area and impacts to neighbors, streams, and wetlands must be conducted using the lower value of aquifer transmissivity. If this lower aquifer transmissivity indicates that the anticipated demand cannot be supported by the aquifer beneath the site, the applicant will need to review and adjust the proposed demand and/or extent of development. The applicant's analysis must use transmissivity data obtained during the pump test.

(e)

The discharge from the test well(s) shall be directed so that it leaves the lot in question without infiltrating to the aquifer and/or impacting the observation wells. The pumped water discharge location must be at least 200 feet downgradient from the test well, whenever possible, and shall not adversely impact adjoining properties. The Township may authorize the use of tanker trucks to contain the water if discharge is not possible due to lot or site conditions. Any and all permits required by the PaDEP and/or local authorities for the discharge of pumped water must be obtained prior to starting the test.

Baseline assessment phase.

Baseline assessment phase testing shall commence no earlier than three days after the well is drilled so that water levels may stabilize.

The pumping equipment must be installed in the pumping well at least 24 hours prior to the start of the baseline assessment phase.

During the baseline assessment phase, a minimum of 24 hours of recording the water level with a five-minute frequency is required. Longer baseline assessment periods, such as one week, may be undertaken to assess ambient fluctuations in the water level. It is the applicant's responsibility to collect sufficient data to determine background conditions and to ensure that antecedent influences can be fully characterized.

Peak demand phase. The purpose of the peak demand phase is to demonstrate that the well can provide the water required for peak usage.

Additional standards. On the day that the peak demand phase begins, water levels shall be collected from the test and observation wells to determine static water level conditions prior to the start of the phase.

Water levels in observation wells on neighboring properties should be allowed to stabilize within 0.5 foot of static prior to the start of pumping in the test well.

For any observation well which has been pumped within the 24 hours preceding the peak demand phase, two depth-to-water measurements, at least one hour apart, shall be collected to assess if the well has fully recovered prior to the start of pumping in the test well.

Peak demand phase duration and water amount.

Class 1 and 2 residential projects.

The flow rate shall be calculated as follows:

Peak demand rate = (no. of bathrooms)(three gallons/minute)

Total daily demand (TDD) must be calculated to determine the duration of the phase. The calculation shall be as follows:

TDD = 100 + [(no. of bedrooms)(100 gallons/day/bedroom)]

The first bedroom in every home shall be assumed to have two people in it (i.e., 200 gal/day). Every additional bedroom is assumed to have one person in it.

[3]

The duration of the phase shall be calculated as follows:

Duration = (0.66)(TDD/peak demand rate)

Class 3 and 4 residential projects. These projects may choose between the Class 1 and 2 residential method, or the method specified for nonresidential projects.

All nonresidential projects, regardless of class.

All nonresidential projects must submit a water use analysis report with a project peak demand model and must include, at a minimum, a definition of duration and peak demand for the proposed project. The applicant shall identify the means used to determine peak demand, and how its model, duration, and demand compare to established reference materials for nonresidential uses [e.g., historic water meter records from equivalent uses/facilities, 25 Pa. Code Ch. 73 on-lot sewage design flow rates, published literature; PaDEP Public Water Supply Manual, most recent version of Guide for Determination of Required Fire Flow by the Insurance Services Office (ISO); American Water Works Association Standards and Manuals].

The water use analysis report with project peak demand model must be approved by the Township in advance of the pump test being conducted. As part of its review, the Township may refer to published estimates of water usage to assist it in evaluating the applicant's proposal.

Swimming pools regardless of project type. Initial filling of new swimming pools, and filling of swimming pools at the beginning of each new season, shall be completed from a source other than an on-site water supply well per Chapter 222. "Top-offs" of already-filled pools from on-site water supply wells are not prohibited, in accordance with Article VI, § 228-26.

Recording protocol for all projects.

Recordings from the test well shall be taken every five seconds for the first two minutes, and then every 20 seconds for the remainder of the duration of the phase.

Recordings from each observation well shall be taken every 20 seconds for the duration of the phase.

Confirmation of meter calibration. A calibrated bucket and stopwatch or a properly sized orifice and manometer system constructed in accordance with the Layne & Bowler protocol must be used to confirm the accuracy of the meter readings. The calibrated bucket and stopwatch method can be used for flow rates less than or equal to 10 gallons per minute. For flow rates in excess of 10 gallons per minute, an orifice and manometer system must be used to determine the flow rate. The flow rate as measured with the bucket/stopwatch shall be recorded periodically to verify consistent flow rate. Orifice and manometer must be recorded at the same frequency and duration as specified for recordings from the test well using a meter. All measurements along with the clock time, and the elapsed time since the peak demand phase started, must be included in the final report.

If the well cannot be pumped at the required flow rate for the required duration, as calculated by the applicant in accordance with this article, the applicant fails the peak demand phase.

Constant head phase. This phase assesses the aquifer's ability to sustainably supply water on a daily basis.

General requirements.

This phase must begin immediately after the peak demand phase without cessation of pumping.

To obtain a constant head pump rate, the flow rate shall be incrementally decreased (or stepped down) from the peak demand rate until a constant head is achieved in test well. A constant head is achieved when the change in head is less than 0.5 foot for a one-hour period after the cessation of the peak demand phase while the test well is being pumped at a flow rate that is equal to or in excess of the total daily demand, but less than or equal to the peak demand rate. If a constant head is not maintained, the applicant fails the constant head phase.

When stepping the flow rate down, the flow rate must be incrementally reduced such that the water level in the well remains within 10 feet of the depth to water measurement made at the end of the peak demand phase. For example, if at the end of the peak demand phase, the water level in the well is 250 feet below ground surface, then for the constant head phase, the water level in the well must be maintained below 240 feet below ground surface. If the water level increases more than 10 feet, then the flow rate should be increased to lower the water level to a point within 10 feet of the depth at which the water level was measured at the end of the peak demand test.

The required duration of the constant head phase, as specified below, shall begin after the constant head is achieved as set forth above.

(e)

If the water level in the test well or any observation well changes more than 0.5 foot per hour, and/or the flow rate drops below the total daily demand, the applicant fails the constant head phase and must restart the pump test at the baseline assessment phase.

(f)

The applicant may not pump the well at a rate lower than what will maintain a constant head in the well, even if the lower rate is still equal to or in excess of the total daily demand. If the applicant violates this provision, the applicant fails the constant head phase and must restart the pump test at the baseline assessment phase.

(g)

All requirements set forth in § 234-112C above shall also be met. To the extent there is a conflict, the stricter provision shall apply.

Constant head phase duration and water amount.

Class 1 and 2 projects. To pass the constant head phase, the applicant must remove a volume of water equal to the TDD while maintaining a constant head pump rate. Duration shall be as follows:

Class 1: minimum of two hours and a maximum of eight hours.

Class 2: minimum of four hours and a maximum of 16 hours.

Class 3 and 4 projects. To pass the constant head phase, the applicant must remove a volume of water equal to twice the TDD while maintaining a constant head pump rate. Duration shall be as follows:

Class 3: minimum of eight hours and maximum of 48 hours.

Class 4: minimum of 16 hours and maximum of 72 hours.

Recording protocol for all projects. Recordings shall be taken from the test well and each observation well every 30 minutes for the duration of the phase.

Recovery phase. This phase is the final step in the pump test.

General requirements.

All pumping must cease, after which recovery in the test well and all observation wells shall be monitored.

Full recovery of total drawdown and to within 0.5 foot of baseline assessment phase conditions must be obtained in all wells.

If such recovery is not obtained within 24 hours of pumping cessation, the well fails the test.

Recording protocol for all projects.

The test well must be monitored every five seconds for the first two minutes after pumping stops, and then every 20 seconds for the remainder of the recovery phase duration.

Observation wells must be monitored every 20 seconds for the duration of the recovery phase.

Extended monitoring phase.

The extended monitoring phase is optional except for Class 3 and 4 applicants when the pumping test results in added drawdown of greater than one foot but less than two feet in any observation well.

The extended monitoring phase consists of the following components, which may be completed in any order:

Forty-five-day period at operating withdrawal schedule.

The purpose of this phase is to determine whether there is a gradual declining trend due to the withdrawal.

During this phase, water levels in the test well shall be recorded over a forty-five-day period at a thirty-minute frequency. The well shall be operated on a cycling schedule based on the anticipated total daily demand and, where present, storage tank volume.

Two-day high-frequency recording ("mini pump test").

The purpose of this component of testing is to accurately characterize the drawdown/recovery relation of the well and aquifer.

This test component consists of high-frequency recording every five seconds over two days. Both water level and flow rate must be monitored.

[a]

During the first part of this test, the pump remains on until a constant head is achieved.

[b]

Once a constant head is achieved, the second part of the test begins. The pump must be shut off and head recovery must be observed. This procedure allows for determining the transmissivity and storage properties of the aquifer in the vicinity of the well.

Analysis of data obtained. The applicant shall compare the data obtained through the extended monitoring phase to expected seasonal water level changes for the local area and the geology in which the test well is proposed. The applicant shall account for measurement noise, and identify to what extent that influences the test results. The applicant shall also determine storage and transmissivity based on data from the mini pump test phase using the Cooper, Bredehoeft, Papadopolos method.

Observation well monitoring.

Observation wells installed by the applicant must be monitored for the duration of the entire extended monitoring phase.

If neighboring wells have been volunteered for observation, they must be monitored unless the neighbors withdraw consent for continued observation during the extended monitoring phase. Retesting is not required if consent is rescinded after the test begins.

Failure standards for observation well added drawdown - required phases of pump test (excluding extended monitoring phase).

If the added drawdown is measured to be more than one foot, but less than two feet, in any observation well, the applicant's qualified hydrogeologist shall perform another pumping test, but with a modified constant head phase.

This modified phase shall be conducted at the same flow rate as the initial pumping test. The use of any lower flow rate will result in test failure.

Duration and yield requirements for modified constant head phase:

Class 1: test well must be pumped to yield one day of TDD while maintaining a constant head condition. If this cannot be done in eight hours or less from when the modified constant head phase began, the test well fails.

Class 2: test well must be pumped to yield two days of TDD while maintaining constant head conditions. If this cannot be done in 48 hours or less from when the modified constant head phase began, the test well fails.

[3]

Class 3: test well must be pumped to yield four days of TDD while maintaining constant head conditions. If this cannot be done in 72 hours or less from when the modified constant head phase began, the test well fails.

[4]

Class 4: test well must be pumped to yield four days of TDD while maintaining constant head conditions. If this cannot be done in 96 hours or less from when the modified constant head phase began, the test well fails.

Further analysis shall also be required by the Township Engineer or an independent qualified hydrogeologist on behalf of the Township, including but not limited to pumping tests of observation wells not volunteered by neighbors.

Class 3 and 4 applicants must also engage in extended monitoring, as set forth in § 234-112H above.

§ 234-113 Observation well requirements.

If added drawdown of two feet or more is measured in any observation well, then the Township shall not issue an approval or permit and the aquifer will be deemed to have insufficient capacity to support the proposed demand and/or extent of development. The applicant shall review and adjust the proposed demand and/or extent of development and proposed well locations to ensure that added drawdown will not exceed two feet in any observation well.

Review of extended monitoring phase data. If the data shows a declining water level over the period of extended monitoring, after a comparison to expected seasonal water level changes and measurement noise, the Township will make a determination based on the data as to whether the applicant must revise the project or take some other action.

Table 234-113: Observation Well Requirements by Project Class
Test Component	Class 1 TDD < 1,000 gpd	Class 2 1,000 < TDD < 2,000 gpd	Class 3 2,000 < TDD < 10,000 gpd	Class 4 TDD > 10,000 gpd
Observation wells required?	Not required if nearest existing well is more than 1,000 feet away from the boundary of the lot on which the test well is proposed. No new observation wells need to be installed. Monitoring wells not required for test new or replacement wells for a single dwelling on a lot existing prior to the date of adoption of this article	If wells exist within 1,000 feet of the boundary of the lot on which the test well is proposed, but are unavailable for testing, then at least one observation well must be installed between the test well and the closest neighboring well.	Same as Class 2 Additionally, if no wells are available within 1,000 feet of the boundary of the lot on which the test well is proposed, one observation well upgradient of the test well and one observation well downgradient of the test well must be installed as close as practical to property boundary but neither observation well may be less than 90° apart.	If wellheads exist within 2,500 feet of the boundary of the lot on which the test well is proposed, but are unavailable for testing, an observation well must be installed as close as possible to the neighboring well. Additionally, if no wellheads are available within 1,000 feet of the boundary of the lot on which the test well is proposed, one observation well upgradient of the test well and one observation well downgradient of the test well must be installed as close as practical to property boundary but neither observation well may be less than 90° apart.
Requests from neighbors	Must accommodate requests from well or other groundwater source owners with such groundwater sources within 1,000 feet of the boundary of the lot on which the test well is proposed	Same as Class 1	Must accommodate requests from well owners or other groundwater source owners with such groundwater sources within 2,500 feet of the boundary of the lot on which the test well is proposed	Same as Class 3

The test well(s) shall not be used to meet the observation well requirements. Multi-well projects should refer back to § 234-111D for requirements on pumping test wells.

Any new wells drilled for observation purposes shall be completed to at least the same depth as the test well and intersect the same beds. In addition, Class 3 and 4 projects must determine the strike and dip of bedding and complete any newly installed observation wells in accordance with the dip trend.

All observation wells must be located and constructed in accordance with the standards set forth in Subarticle XIVC.

The Township, in its review of the applicant's plans, may require additional observation wells, changes in the location of proposed new observation wells, or other revisions pertaining to observation wells to ensure an accurate analysis of, among other things, potential impacts to neighbors.

The Township may also authorize the applicant to use any existing wells on the lot as observation wells.

All observation wells installed as part of the pump test and that will not be used as part of the development or other land use shall be properly abandoned in accordance with Subarticle XIVC, unless the Township requires any such observation wells to be retained as a permanent monitoring well, in which case the well must be properly secured with a locking cap.

Well casings and ground surface elevations for the test well and the observation wells shall be surveyed to a common datum.

The location of all test and observation wells shall be recorded by latitude/longitude coordinates (NAD 83) together with the USGS Datum elevation of the wellhead casing. The horizontal location of the well should be accurate to within +/— 10 feet and the elevation above the USGS Datum to within one foot.

§ 234-114 Neighbor notification requirements.

Notification.

The applicant shall notify owners of existing wells and other groundwater sources (e.g., springs) with such water sources located within 1,000 feet (for Classes 1 and 2) and 2,500 feet (for Classes 3 and 4) of the boundary of the lot on which the test well is proposed (the "neighbor notification distance") and shall be given an opportunity to have their wells/springs monitored during groundwater pump testing.

The applicant must send notice via certified mail at least 45 days prior to the pump test to every qualifying property owner within the neighbor notification distance and shall state the time and place of the pump test. An example notice acceptable to the municipality, and sample access agreement, is included as Appendix A.[1]

Editor's Note: Appendix A is included as an attachment to this chapter.

The notice shall indicate that such existing well or other wellhead may be monitored, if agreed to by the wellhead owner, provided the wellhead is readily accessible as determined by the Township Engineer. Such notice shall indicate that the wellhead owner must respond within seven days of notice receipt and the applicant's responsibility is to monitor groundwater sources on properties located within the neighbor notification distance when such owners request monitoring (where wells are reasonably accessible), and the Township and, where applicable, BCHD, PaDEP and/or DRBC, approves monitoring of volunteered wells.

The applicant shall provide a certificate of insurance for itself and all contractors utilized and pay all costs associated with the monitoring of any existing residential well or other residential groundwater source.

(5)

All wells and equipment installed in each well or other groundwater source shall be disinfected each time they are opened for service or monitoring, unless the owner specifically waives the requirement for disinfection in writing.

(6)

The costs of extending, restoring or replacing a well and any ancillary well equipment (e.g., well hardware such as pumps and wires), or restoring or replacing any other groundwater source damaged as a result of testing shall be the responsibility of the applicant.

(7)

The applicant shall indemnify and hold the Township and its consultants and representatives harmless from any liability in connection with these testing requirements.

Response.

If the owner of a well or other groundwater source within the neighbor notification distance volunteers to have his/her existing well or other groundwater source monitored, such owner shall notify the applicant by certified mail or such other means that provide proof of when the notification was sent.

Such response shall be sent within seven days of receipt of the certified notice from the applicant.

If the applicant receives no response within 14 days of when the applicant sent the certified notice, the response shall be deemed to be negative.

Protection of monitored groundwater source and selection of sources for monitoring.

All reasonable efforts must be made to protect the potability of water from the monitored well or other groundwater source.

In the case when more than three water well or other groundwater source owners within the neighbor notification distance decide to participate and to have their existing wells or other groundwater sources monitored, the applicant shall consult with the Township and, as applicable, BCHD, PaDEP and/or DRBC, to determine a maximum number of wells to be monitored.

A map depicting the location of all wells or other groundwater sources to be monitored and a list of all individuals within the neighbor notification distance that requested monitoring is to be submitted to the Township's qualified hydrogeologist for review and approval prior to implementing the test.

§ 234-115 Additional groundwater sustainability analyses.

The observation wells and other groundwater sources on neighboring properties should be selected to assess the water-level drawdown impacts from the test well.

(5)

The Township reserves the right to retain a qualified hydrogeologist to review the proposed monitoring locations and to make recommendations to revise the locations to be monitored.

This section specifies additional analyses to determine impacts to neighboring wells, perennial streams, ponds, lakes, reservoirs, and/or wetlands. When these analyses are required, as described below, they must be conducted. Septic system discharges may not be used in recharge calculations.

Contributing area analysis. This analysis examines how the addition of a new groundwater well within a certain distance of an existing well affects the contributing area to the existing well at the proposed well's total daily demand.

Thresholds for the analysis. An applicant must conduct a contributing area analysis under the following circumstances:

Class 1: when an existing well is within 200 feet of a proposed new well, and that existing well is not available for observation. Contributing area analysis is not required for new or replacement wells for single dwellings constructed on lots existing prior to the date of adoption of this article, or new single well/lot residential projects.

Class 2: when an existing well is within 500 feet of a proposed new well, and that existing well is not available for observation.

Class 3: when an existing well is within 1,000 feet of a proposed new well, and that existing well is not available for observation.

Class 4: when an existing well is within 2,500 feet of a proposed new well, and that existing well is not available for observation.

Analysis.

Applicants must all use data obtained from the pump testing process, including any quantity data obtained from neighboring wells volunteered for observation during the testing.

When existing wells within the analysis range are present, but are not volunteered for observation, the applicant must also use existing water quantity data and assumed operating conditions of the unmonitored existing wells to model the contributing area impact. The existing data must be representative of the geology in which the existing and proposed wells are located. Operating conditions assumed based on the unmonitored existing wells must be consistent with the type of land use being served by the well(s) and existing literature on typical water demands. When modeling the impact, the assumptions on which the applicant's model is based must be applicable to the geologic and other site conditions on the lot and the surrounding area. The model used by the applicant must also be one commonly used by qualified hydrogeologists.

Failure standards.

When actual data exists from neighboring wells, the failure standards for the contributing area analysis shall be the same as the observation well added drawdown failure standard for the pump test.

When an applicant must model the impact on neighboring wells, the following failure standards apply:

If the added drawdown is projected to be more than one foot, but less than two feet, at any existing unmonitored well, the applicant's qualified hydrogeologist shall engage in modeling that has a modified constant head phase as set forth under § 234-112I(1). Further analysis shall also be required by the Township Engineer or an independent qualified hydrogeologist on behalf of the Township.

If added drawdown of two feet or more is projected in any existing unmonitored well, then the aquifer will be deemed to have insufficient capacity to support the proposed demand and/or extent of development. The applicant will be required to review and adjust the proposed demand and/or extent of development and proposed well locations to ensure that added drawdown will not exceed two feet in any existing unmonitored well.

Baseflow analysis. This analysis examines whether a proposed well will reduce or eliminate baseflow to nearby perennial streams and/or nearby wetlands, lakes, ponds, and/or reservoirs at the proposed well's total daily demand or otherwise adversely reduce or eliminate recharge to such water resources due to increased withdrawal density.

Thresholds for the analysis. Except as provided in § 234-115B(4), an applicant must conduct a baseflow analysis under the following circumstances:

Class 1: if a perennial stream or a wetland, lake, pond, and/or reservoir is within 250 feet of the proposed well, or the proposed withdrawal density is greater than 100 gallons per acre per day (g/a/d). The baseflow analysis is not required for new or replacement wells for single dwellings constructed on lots existing prior to the date of adoption of this article, or new single well/lot residential projects.

Class 2: if a perennial stream or a wetland, lake, pond, and/or reservoir is within 500 feet of the proposed well, or the proposed withdrawal density is greater than 100 g/a/d.

Class 3: if a perennial stream or a wetland, lake, pond, and/or reservoir is within 1,000 feet of the proposed well, or the proposed withdrawal density is greater than 100 g/a/d.

Class 4: required for all applicants regardless of distance to nearest perennial stream or nearest wetland, lake, pond, and/or reservoir, and regardless of withdrawal density.

Analysis.

Applicants must use all data obtained from the pump testing process, including any quantity data obtained from observation wells, including from neighboring wells volunteered for observation during the testing.

Applicants may either model the impact of the test well or choose to install one or more piezometers and stream gauges to assist with the baseflow analysis. If the applicant installs stream or other surface monitoring devices, it shall follow protocols and guidance established by the DRBC, PaDEP, and/or Susquehanna River Basin Commission. If the applicant models the impact, all assumptions on which the model is based must be applicable to the geologic and other site conditions on the lot and the surrounding area. The model must also be one commonly used by qualified hydrogeologists.

Failure standards. If drawdown is measured or projected:

To induce leakage from perennial streams and/or from wetlands, lakes, ponds, and/or reservoirs; and/or

Deplete recharge, such that baseflow in such water resources will be diminished, depleted, or dewatered either in the short-term or over time, then the proposed demand and/or extent of development must be reduced to prevent adverse impacts to the perennial streams and the wetlands, lake, pond, and reservoir.