Return to: TABLE OF CONTENTS, Water Quality Home Page, DEQ Home Page
DEQ's AND OHD's RULES
Oregon's Wellhead Protection Program
will be accomplished through rules administered by both DEQ and OHD. The purpose of rules
to accomplish a voluntary program are two-fold (Table 2-1):
Under their statutory authorities, OHD's rules
provide for the delineation, contingency, and new wells elements of wellhead protection. DEQ's rules provide for all other elements, overall administration
of the program, as well as the final certification of the local plans.
Table 2-1: Index of Information on Rule Requirements
Corresponding Information in Guidance Manual
Section / Page
Specification of duties for local plans
|Roles of Responsible Management Authorities (RMAs).||Section 1.5 / p. 1-13|
|Signoff by RMAs.||Section 1.6 / p. 1-16|
Delineation of wellhead protection areas
|OHD technical guidance for delineation.||Section 3.3 / p. 3-4|
|Example delineation methods.||Appendix A / p. A-1|
Inventory of potential contaminant sources
|DEQ guidance for inventory.||Section 3.4 / p. 3-32 &|
|Examples of inventory maps.||Appendix C / p. C-1|
Developing management plan to address potential sources
|DEQ technical assistance for management approach.||Section 3.5 / p. 3-47|
|Example ordinance.||Appendix E / p. E-1|
|Pollution prevention information.||Appendix F / p. F-1|
|Example homeowner letter.||Appendix G / p. G-1|
|Household hazardous waste information.||Appendix H / p. H-1|
New and future groundwater sources
|OHD technical guidance for new and future sources.||Section 3.7 / p. 3-85|
|OHD guidance for developing a contingency plan.||Section 3.6 / p. 3-84|
|Example contingency plan.||Appendix I / p. I-1|
|Soliciting public involvement.||Section 3.1 / p. 3-1|
|Example notification letter.||Appendix G / p. G-1|
|Formation of a local Team.||Section 3.2 / p. 3-3|
|Requirements and method for obtaining certification from OHD and DEQ.||Section 3.8 / p. 3-88|
Procedure for recertification and
|DEQ guidance for recertification, revisions, updates & decertification.||Section 3.8 / p. 3-89|
Appeals to DEQ decisions
|Procedure for local jurisdictional appeal of DEQ's decisions regarding certification issues.||Section 3.8 / p. 3-89|
DEQ - OAR 340-40-140 through 340-40-210 (Back to Top)
ORS 468.035; ORS 468B.015(2);
STATEMENT OF PURPOSE
(1) Meet Federal Requirements: The intent of these rules is to fulfill
the Federal requirements under the Safe Drinking Water Act for the establishment of
a state Wellhead Protection Program.
(2) Protect Public Water Systems: The purpose of a Wellhead Protection
Plan is to protect the groundwater relied upon by a public water system from
contamination. This is accomplished by reducing the risk of contamination to the
groundwater from potential sources.
(3) Establish Voluntary Wellhead Protection Program: Local jurisdictions
and/or public water systems may voluntarily develop a Wellhead Protection Plan, but are
not required, by these rules, to do so.
(4) Procedures for State Approval: These rules establish a process to
enable the Department to certify a local Wellhead Protection Plan if it is submitted for
certification, and to establish the process for a Responsible Management Authority, if
they choose, to seek certification from the Department for a locally developed Wellhead
(1) "Contingency Plan" means a document setting out an
organized, planned and coordinated course of action to be followed in the event of a loss
of capacity to supply water to the distribution system or in case of a fire, explosion, or
release of hazardous waste or hazardous waste constituents which could threaten human
health or the environment.
(2) "Department" means the Department of Environmental
(3) "Delineation" means the determination of the extent,
orientation, and boundaries of a wellhead protection area using factors such as geology,
aquifer characteristics, well pumping rates, and time of travel.
(4) "Element" means one of seven components considered by the
U.S. Environmental Protection Agency as the minimum required components in any state
wellhead protection program: specification of duties, delineation of the wellhead
protection area, inventory of potential contaminant sources, specification of management
approaches, development of contingency plans, addressing new (future) wells and springs,
and ensuring public participation.
(5) "Governmental Entity" means any local, state, Indian
tribe, or federal organization or agency which may own or manage lands or activities
within a Wellhead Protection Area.
(6) "Plan" means Wellhead Protection Plan.
(7) "Potential Contaminant Source" means any activity which
has the potential to release contaminants to the groundwater.
(8) "Public Water System" means a system supplying water for
human consumption that has four or more service connections or supplies water to a public
or commercial establishment which operates a total of at least 60 days per year, and which
is used by 10 or more individuals per day.
(9) "Responsible Management Authority" means a Public Water System whose water supply is being protected and any governmental entity with management, rule or ordinance making authority to implement wellhead protection management strategies within a Wellhead Protection Area. Responsible Management Authorities are responsible for implementation of the Wellhead Protection Plan; includes cities, counties, special districts, Indian tribes, state/federal government entities as well as Public Water Systems.
(10) "Signatory" means any Responsible Management Authority in
the Wellhead Protection Area who signs the Wellhead Protection Plan. Signing the plan
indicates the Responsible Management Authority will implement the actions outlined for
their jurisdiction in the plan.
(11) "Stakeholder(s) means person(s) and/or governmental
entity(ies) who could or will be affected by activities or requirements that may be
required within a local wellhead protection area.
(12) "Team" means the local Wellhead Protection Team; which includes representatives from the Responsible Management Authorities and various interests and stakeholders potentially affected by the Wellhead Protection Plan.
(13) "Wellhead Protection Area" means the surface and
subsurface area surrounding a water well, spring or wellfield, supplying a public water
system, through which contaminants are reasonably likely to move toward and reach that
water well, spring or wellfield.
(14) "Wellhead Protection Plan" refers to a Department
certified plan which identifies the actions to be taken at the local level to protect a
specific defined Wellhead Protection Area. The Plan is developed by the local Responsible
Management Authority(ies) and/or team and includes a written description of each element,
public participation efforts, and an implementation schedule.
(1) It is the policy of the state to promote the protection of the
quality of the groundwater resource from contamination by encouraging public water systems
and/or governmental entities to voluntarily develop local Wellhead Protection Plans to
protect the groundwater resources which a Public Water System relies upon for its drinking
(2) A certified Wellhead Protection Plan will be recognized as meeting
the Wellhead Protection requirements under the Federal Safe Drinking Water Act of 1986,
Section 1428 (42 USC 300F to 300J - 26).
(3) The Department will coordinate and work cooperatively with the
Health Division, Department of Agriculture, Water Resources Department, Department of Land
Conservation and Development and other governmental entities to promote the voluntary
development of Wellhead Protection Plans.
(4) Other state rules may apply and may or may not pertain to the
delineated Wellhead Protection Area, including but not limited to the rules of those
agencies listed in Section (3) of this rule.
(5) The Department will, within available resources, provide information
and technical assistance to local Wellhead Protection Teams and other interested parties
in the development of their Wellhead Protection Plans.
(6) All Responsible Management Authorities who have jurisdiction within
a Wellhead Protection Area are encouraged to work together to develop a Plan to manage
those activities that may have the potential to contaminate groundwater within that
Wellhead Protection Area.
(7) Implementation of a Wellhead Protection Plan shall rely upon
existing enforcement capabilities of the Responsible Management Authorities within the
delineated Wellhead Protection Area. Nothing in these rules will modify or change existing
authorities or requirements put in place through other statutes or rules.
(8) The Department shall maintain a guidance manual to assist
Responsible Management Authorities and Wellhead Protection Teams in the development of a
state certifiable Wellhead Protection Plan. This manual is intended solely to provide
information and assistance in identifying strategies for developing a Wellhead Protection
Plan. The guidance manual provides examples of how a protection plan could be developed to
meet the requirements of these rules to gain Department certification as a Wellhead
Protection Plan. It does not contain mandatory standards or other legal requirements nor
does it include binding statements or interpretations of law or agency policy.
REQUIRED ELEMENTS OF A WELLHEAD PROTECTION PLAN
(1) A Wellhead Protection Plan shall contain and address the following seven elements: (Back to Table 2-1)
(a) Specification of duties:
(A) The Plan shall identify all the Responsible Management Authorities
within a Wellhead Protection Area. The jurisdictional boundaries of each Responsible
Management Authority shall be shown on a map;
(B) For each Responsible Management Authority identified, the
expectations, their respective responsibilities, and the duties they will perform with
regards to implementing the Plan must be identified;
(C) The Plan shall either:
(i) Have all Responsible Management Authorities in the Wellhead Protection Area sign the Wellhead Protection Plan indicating that they will implement the actions outlined for their jurisdiction in the plan; or
(ii) Describe the procedure used to notify and attempt to involve those
Responsible Management Authorities not willing to sign the plan.
(b) Delineation of Wellhead Protection Areas: Delineation of Wellhead
Protection Areas shall occur as described under Health Division's rules under OAR
(c) Inventory of Potential Contaminant Sources:
After delineation of the Wellhead Protection Area, an inventory identifying the potential
sources of contamination within the Wellhead Protection Area shall be completed. The
inventory shall be designed to identify: (Back to Table 2-1)
(A) Past practices which may have resulted in a potential threat to the
(B) Those potential sources of contamination presently existing; and
(C) Those potential sources which may exist in the future.
(d) Management of Potential Sources of
(Back to Table 2-1)
(A) For those potential sources of contamination identified under the
inventory element of paragraphs (1)(c)(A),(B), and (C) of this rule, the Plan shall
identify the management action to be employed to reduce the risk of contamination to the
groundwater from those source(s) and justification for the proposed management actions and
level of protection provided;
(B) The Plan must identify the process used to address unanticipated
potential sources of contamination that may locate within the Wellhead Protection Area,
how the source will be evaluated for acceptability within the area, and how the management
actions identified in the Plan for reducing the risk of contamination will be implemented.
(C) Any management plans that directly regulate farming practices for
the purpose of protecting water quality on agricultural lands within a Wellhead Protection
Area shall be developed and implemented by the Oregon Department of Agriculture in
accordance with Oregon Department of Agriculture authorities.
(e) Contingency Plan: Development of contingency plans for Wellhead Protection Areas shall be in accordance with Health Division rules under OAR 333-61-057(4);
(f) Siting of New Public Water System Wells or Springs: Siting of new
public water system wells or springs shall be in accordance with Health Division rules
under OAR 333-61-057(3);
(g) Public Participation: A description of the
public participation efforts shall be included in the Plan, including:
(Back to Table 2-1)
(A) Documentation that property owners and residents within the Wellhead
Protection Area were notified of the development of a Wellhead Protection Plan.
Notification at a minimum shall include publication of the intent to develop a Wellhead
Protection Plan in a local newspaper and a description of the process for developing and
participating in the development of the Wellhead Protection Plan;
(B) Formation of a Team to develop the Plan. The Team can either be a new group formed for the specific purpose of developing a plan or it can be an existing group that is assigned the additional duty of developing a Plan;
(C) Description of steps taken to provide opportunity for various interests within the affected area to participate;
(D) Documentation that all local public hearing procedures were followed
in developing and adopting the Plan.
340-40-180 (Back to Table 2-1)
(1) For a Wellhead Protection Plan to be certified by the Department,
the plan must meet requirements specified in OAR 340-40-170.
(2) The Department shall act as the contact point for development and approval of Wellhead Protection Plans. The Department shall coordinate with other governmental entities so that the Plan is consistent with the requirements of those governmental entities before Department certification of the Plan is granted.
(3) The Health Division shall be responsible for certifying the
delineation, and reviewing contingency plans and the new wells elements of the plan as
provided for under OAR 333-61-020 through 333-61-065. The Department shall accept the
Health Division's recommendations and certification.
(4) After consultation with the Department of Agriculture on agricultural issues, the Department of Land Conservation and Development on land use issues, the Health Division and other governmental entities as appropriate, the Department shall be responsible for reviewing the remaining elements and giving the overall certification for each local Wellhead Protection Plan if each element is found to be adequately addressed.
(5) Within 60 days of the receipt of a request for certification of a
Wellhead Protection Plan, the Department will send a written acknowledgment of receipt of
the request and an estimated date for Department review and certification of the plan.
(6) After certification of the plan, the Department will provide a
written certification of completion to all signatories to the plan.
340-40-190 (Back to Table 2-1)
(1) A Wellhead Protection Plan must be recertified every five years from
the date of prior Department certification.
(2) Recertification of the present Plan can take place if all the
following conditions apply:
(a) No conditions that could potentially modify the boundaries of the
Wellhead Protection Area have occurred;
(b) An updated inventory is completed and submitted which shows that no
new potential sources of contamination have moved into the Wellhead Protection Area which
are not addressed in the existing Plan;
(c) The management practices outlined in the existing Plan are still
appropriate and being implemented;
(d) The existing contingency element in the Plan is still relevant; and
(e) All signatories to the existing Plan agree to recertify the Plan by
signing the recertification request letter.
(3) If a certified Plan cannot meet the conditions under section (2) of
this rule, then a revised Wellhead Protection Plan must be resubmitted for certification.
A revised plan shall require:
(a) Form a Team to develop the Plan. The Team can either be a new group
formed for the specific purpose of developing a Plan or it can be an existing group that
is assigned the additional duty of developing a Plan;
(b) Identify the elements under OAR 340-40-170 where the Plan is no
longer adequate or relevant;
(c) Modify the Plan in those areas identified in subsection (b) of this
section to meet conditions outlined in OAR 340-40-170 and 180;
(d) Perform and submit a new potential source inventory; and
(e) Submit to the Department for review and certification per OAR
340-40-200 (Back to Table 2-1)
(1) If the signatories to a Wellhead Protection Plan do not recertify or
submit for recertification their previously certified Wellhead Protection Plan, then the
Plan is automatically decertified until such time as the signatories of the Plan recertify
the Plan through the update procedure per OAR 340-40-190.
(2) Any Responsible Management Authority that is a signatory to a
certified Plan shall have the ability to withdraw from participation in a Wellhead
Protection Plan and the certification process. The Department shall review the plan to
determine if the plan is still certifiable without the participation of the withdrawing
Responsible Management Authority.
(3) A plan can also be decertified by the Department if it comes to the
Department's attention that a signatory to a Plan is not or has not adhered to and
implemented the certified Plan.
(4) To decertify a Wellhead Protection Plan, the Department will send a
certified letter to all signatories to the Plan detailing the reason(s) why the Department
believes the certified Plan is or was not being followed or is no longer valid and the
Department's intent to decertify the Plan.
(a) The signatories to the Plan will have 30 days to respond as to why
their Plan should not be decertified;
(b) The Department will review the signatories response and make a
determination as to whether the Plan is still certifiable;
(c) The Department will then send a copy of its decision to all
signatories of the Plan;
(5) The Department will afford the remaining signatories the opportunity
to maintain the certification, provided withdrawal by a Responsible Management Authority
does not render the Plan uncertifiable, by notifying the Department and all other
Responsible Management Authorities within the Wellhead Protection Area that they will
continue to implement the plan as certified in their respective jurisdictions.
340-40-210 (Back to Table 2-1)
Final Department decisions regarding certification, recertification, or
decertification are not subject to contested case hearing rights but are reviewable under
OHD - OAR 333-61-020, -050, -057, and -065 (Back to Top)
ORS 448.131(2)(a), (c);
ORS 448.160; ORS 672.525
(1) Aquifer. A water saturated and permeable geological formation, group
of formations, or part of a formation that is capable of transmitting water in sufficient
quantity to supply wells or springs.
(2) Aquifer Parameter. A characteristic of an aquifer, such as
thickness, porosity and hydraulic conductivity.
(3) Aquifer Test. Pumping a well in a manner that will provide
information regarding the hydraulic characteristics of the aquifer.
(4) Average Groundwater Velocity. The average velocity at which
groundwater moves through the aquifer as a function of hydraulic gradient, hydraulic
conductivity and porosity.
(5) Calculated Fixed Radius. A technique to delineate a wellhead
protection area, based on the determination of the volume of the aquifer needed to supply
groundwater to a well over a given length of time.
(6) Conceptual Model. A three-dimensional representation of the
groundwater system, including the location and extent of the hydrogeologic units, areas of
recharge and discharge, hydrogeologic boundaries and hydraulic gradient.
(7) Contingency Plan. A document setting out an organized, planned and
coordinated course of action to be followed in the event of a loss of capacity to supply
water to the distribution system or in case of a fire, explosion, or release of hazardous
waste or hazardous waste constituents which could threaten human health or the
(8) Delineation. The determination of the extent, orientation and
boundaries of a wellhead protection area using factors such as geology, aquifer
characteristics, well pumping rates and time of travel.
(9) Discharge. The volume rate of loss of groundwater from the aquifer
through wells, springs or to surface water.
(10) Drawdown. The difference, measured vertically, between the static
water level in the well and the water level during pumping.
(11) Effective Porosity. The ratio of the volume of interconnected voids
(openings) in a geological formation to the overall volume of the material.
(12) Element. One of seven objectives considered by the U.S.
Environmental Protection Agency as the minimum required components in any state wellhead
protection program: specification of duties, delineation of the wellhead protection area,
inventory of potential contaminant sources, specification of management approaches,
development of contingency plans, addressing new (future) wells, and ensuring public
(13) Future Groundwater Sources. Wells and/or springs that may be
required by the public water system in the future to meet the needs of the system.
(14) Hydraulic Head. The energy possessed by the water mass at a given
point, related to the height above a datum plane that water resides in a well drilled to
that point. In a groundwater system, the hydraulic head is composed of elevation head and
(15) Hydrogeologic Boundary. Physical features that bound and control
direction of groundwater flow in a groundwater system. Boundaries may be in the form of a
constant head, e.g., streams, or represent barriers to flow, e.g., groundwater divides and
impermeable geologic barriers.
(16) Hydrogeologic Mapping. Characterizing hydrogeologic features (e.g.,
hydrogeologic units, hydrogeologic boundaries, etc.) within an area and determining their
location, areal extent and relationship to one another.
(17) Hydrogeologic Unit. A geologic formation, group of formations, or
part of a formation that has consistent and definable hydraulic properties.
(18) Interfering Wells. Wells, that because of their proximity and
pumping characteristics, and as a result of the aquifer's hydraulic properties, produce
drawdown cones that overlap during simultaneous pumping. The result is a lowering of the
pumping level in each well below what it would be if that well were pumping by itself.
(19) New Groundwater Sources. Additional or modified wells and/or
springs owned by the Public Water System.
(20) Open Interval. In a cased well, the open interval is the sum of the
length(s) of the screened or perforated zone(s). In an uncased (open-hole) well, the open
interval is considered as the sum of the thickness(es) of the water-bearing zones, or if
undeterminable, 10 percent of the length of the open hole.
(21) Porous Media Assumption. The assumption that groundwater moves in
the aquifer as if the aquifer were granular in character, i.e., moves directly
downgradient, and the velocity of the groundwater can be described by Darcy's Law.
(22) Potential Contaminant Source Inventory. Determination of the
location within the wellhead protection area of activities known to use or produce
materials that can contaminate groundwater.
(23) Potentiometric Surface. A surface that denotes the variation of
hydraulic head in a given aquifer across an area.
(24) Provisional Delineation. Approximating the wellhead protection area
for a well by using the wellhead protection area from another well in the same
hydrogeologic setting or by using generalized values for the aquifer characteristics to
generate an approximate wellhead protection area for the well. Used only for the purpose
of evaluating potential siting of new or future groundwater sources. Not an acceptable way
to formally delineate a wellhead protection area.
(25) Recharge. The process by which water is added to a zone of saturation, usually by downward infiltration from the surface.
(26) Recharge Area. A land area in which water percolates to the zone of
saturation through infiltration from the surface.
(27) Recovery. The rise in water level in a well from the pumping level
towards the original static water level after pumping has been discontinued.
(28) Responsible Management Authority. The Public Water System whose
water supply is being protected and any governmental entity having management, rule or
ordinance making authority to implement wellhead protection management strategies within a
Wellhead Protection Area. Responsible Management Authorities are responsible for
implementation of the Wellhead Protection Plan; includes cities, counties, special
districts, Indian tribes, state/federal government entities and Public Water Systems.
(29) Team. The local Wellhead Protection team, which includes
representatives from the Responsible Management Authorities and various interests and
stakeholders potentially affected by the Wellhead Protection Plan.
(30) Time-of-Travel (TOT). The amount of time it takes groundwater to
flow to a given well. The criterion that effectively determines the radius in the
calculated fixed radius method and the upgradient distance to be used for the analytical
and numerical models during delineation of the wellhead protection area.
(31) Water-Bearing Zone. That part or parts of the aquifer encountered
during drilling that yield(s) water to the well.
(32) Water Table. The upper surface of an unconfined aquifer, the
surface of which is at atmospheric pressure and fluctuates seasonally. The water table is
defined by the levels at which water stands in wells that penetrate the aquifer.
(33) Wellhead Protection. Implementing strategies within a wellhead
protection area to minimize the potential impact of contaminant sources on the quality of
groundwater used as a drinking water source by a public water system.
(34) Wellhead Protection Area (WHPA). The surface and subsurface area
surrounding a spring, well or wellfield, supplying a public water system through which
contaminants are reasonably likely to move toward and reach that spring, well or
(35) Wellhead Protection Plan. A plan, certified by the Department of
Environmental Quality (DEQ), which identifies the actions to be taken at the local level
to protect a specifically defined wellhead protection area. The Plan is developed by the
local Responsible Management Authority and/or team and includes a written description of
each element, public participation efforts, and an implementation schedule.
(a) A public water system or other Responsible Management Authority
using groundwater, or groundwater under the direct influence of surface water, derived
from springs, confined- or unconfined wells that wishes to have a state certified wellhead
protection program shall comply with the requirements as specified in OAR 333-61-057,
333-61-060, and 333-61-065, as well as OAR 340-40-140 through 340-40-200 and other
applicable rules. Additional technical information is available in the Oregon Wellhead
Protection Guidance Manual.
VOLUNTARY WELLHEAD PROTECTION PROGRAM
(1) In accordance with OAR 340-40-140 through
340-40-200, a public water system or other Responsible Management Authority that wishes to
have a state certified wellhead protection program shall comply with the requirements
prescribed in this rule.
(2) Delineation of the wellhead protection area
(WHPA). (Back to Table 2-1)
(a) Delineation requirements for all groundwater sources are as follows:
(A) Delineations will be accomplished using a minimum TOT criterion of
10 years unless a hydrogeologic boundary is encountered at a shorter time of travel or as
specified in paragraph (2)(c)(B) of this rule;
(B) Delineations will be accomplished by a registered geologist,
engineering geologist or other licensed professional with demonstrated experience and
competence in hydrogeology in accordance with ORS 672.505 through 672.705.
(C) Except as noted in paragraph (2)(c)(B) of this rule, a conceptual
groundwater model shall be developed for all public water systems participating in the
voluntary wellhead protection program. The conceptual model shall be based on available
information, including but not limited to: well reports, published reports and available
unpublished reports and theses, etc. Sources of this information include the Water
Resources Department, U. S. Geological Survey, Department of Geology and Mineral
Industries, Department of Environmental Quality, University Libraries and the Division.
The conceptual model shall include, but not be limited to, the identification and
characterization of hydrogeologic units, determination of hydrogeologic boundaries, if
any, areas of discharge and recharge and distribution of hydraulic head for the aquifer(s)
of concern. The conceptual model shall also evaluate whether or not the porous media
assumption is valid.
(D) The delineated WHPA and supporting documentation shall be submitted
to the Division for review and certification.
(E) Within 60 days of the receipt of the delineated wellhead protection
area and supporting documentation, the Division will send a written acknowledgment of that
receipt and an estimated date for Division review and certification of the delineation.
(F) The delineation techniques stipulated in this rule represent the
minimum acceptable effort required for a state certified program. The use of a more
sophisticated technique is acceptable.
(b) Springs. For water systems served by springs, hydrogeologic mapping
shall be used to delineate the recharge area to the spring(s);
(A) All delineations for groundwater derived from wells shall use a
adjusted pump rate (Qa) that allows for potential growth using one of the
methods below, whichever yields the smallest value for Qa:
(i) 125 percent of average pump rate as determined from the month
representing the highest usage;
(ii) 125 percent of average pump rate as determined using a comparable
(iii) The design capacity of the pump; or
(iv) 90 percent of the safe yield of the well.
(B) For water systems serving £ 500 population, the minimum acceptable delineation method is a calculated fixed
radius. Parameters considered in this technique include Qa, effective porosity,
open (screened or perforated) interval or thickness of the water-bearing zone(s),
whichever is less, and a TOT of 15 years;
(C) For water systems serving 501 to 3,300, the WHPA(s) shall be
delineated using a combination of an analytical technique and hydrogeologic mapping;
(D) For water systems serving > 3,300, the conceptual model shall be
refined using site-specific collected data. Data collected shall include, but not be
limited to, measured static water levels for the purpose of generating a map of the
appropriate potentiometric-or water table surface, and at a minimum a 24-hour
constant-rate aquifer test. The well to be tested should remain idle for a period of 24
hours prior to the test. Water levels in the well should be monitored at appropriate
intervals during the pre-pumping-, pumping-and recovery phases. Additional technical
information is given in the Oregon Wellhead Protection Guidance Manual;
(E) For water systems using wells and serving a population of 3,301 to
50,000, the WHPA(s) shall be delineated as provided in paragraph (C) of this subsection,
with the exception of using the site specific data collected in accordance with paragraph
(D) of this subsection;
(F) For water systems serving a population >50,000, the WHPA(s) shall
be delineated using numerical models or comparable analytical methods. The model must be
calibrated using field observations and measurements of appropriate hydrogeologic
(d) Susceptibility Analysis. To guide the development of management
strategies, the aquifer's susceptibility within the WHPA may be determined using the
methods described in the Use and Susceptibility Waiver Guidance Document or another
pre-approved process. Additional technical information is available in the Oregon Wellhead
Protection Guidance Manual;
(e) Delineation Update. The public water supply's WHPA delineation shall
be re-examined every five years for potential revisions (OAR 340-40-190). Factors that may
require revision of a WHPA boundary include, but are not limited to the following:
(A) A significant change in the pumping rate;
(B) A significant change in recharge to the aquifer;
(C) Wells outside the control of the water system placed in a manner
that could significantly modify the shape and/or orientation of the original WHPA.
(3) New and Future Groundwater Sources. (Back to Table 2-1)
(a) New Sources. With regard to the voluntary wellhead protection
program, a new source is defined as an additional or modified well(s) and/or spring(s)
that will be used by the water system:
(A) For new wells or springs outside an existing WHPA or deriving water
from a different aquifer than that supplying other already delineated WHPAs, the following
shall be completed:
(i) If more than one potential site is available, the water system or
other responsible management authority shall conduct a provisional delineation and a
preliminary potential contaminant source inventory for each site being considered in order
to evaluate the long-term viability of each of the sites available.
(ii) Delineate the chosen site following procedures in section (2) of
this rule. Further technical information is provided in the Oregon Wellhead Protection
(B) For new wells or springs inside an existing WHPA or potentially
influencing an existing WHPA, the following shall be completed:
(i) Evaluate sites and delineate WHPA(s) as described in subparagraphs
(3)(a)(A)(i) and (ii) of this rule;
(ii) Modify the existing wellhead protection plan to encompass modifications resulting from the new delineation.
(C) New wells or springs as defined in subsection (3)(a) of this rule
shall comply with all appropriate construction standards as described in OAR 333-61-050
and shall comply with plan submission requirements in OAR 333-61-060.
(b) Future Sources. A public water system or other responsible
management authority that has recognized the need for future groundwater supplies beyond
their current capacity may choose to identify the area where this future supply will be
obtained in accordance with subparagraph (3)(a)(A)(i) of this rule.
(4) Contingency Planning. (Back
to Table 2-1)
(a) Public water systems shall develop or revise contingency plans for response to potential loss or reduction of their drinking water source(s). Key elements of the plan shall in
clude, but not be limited to, the following:
(A) Inventory/prioritize all threats to the drinking water supply;
(B) Prioritize water usage;
(C) Anticipate responses to potential incidents;
(D) Identify key personnel and development of notification roster;
(E) Identify short-term and long-term replacement potable water
(F) Identify short-term and long-term conservation measures;
(G) Provide for plan testing, review and update;
(H) Provide for new and on-going training of appropriate individuals;
(I) Provide for education of the public; and
(J) Identify logistical and financial resources.
(b) Public water systems shall coordinate their contingency plan with
the emergency response plans of the appropriate county and/or city and with the
contingency plans developed by industries using hazardous materials within the well head
OPERATION AND MAINTENANCE
...(d) Implementing actions to assure safe drinking water during emergencies. Water systems wishing to have a state certified wellhead protection program shall comply with the contingency planning requirements as described in OAR 333-61-057(4).
Return to Top of Chapter 2
Return to: TABLE OF CONTENTS, Water Quality Home Page, DEQ Home Page