Skip to main content
Loading…
This section is included in your selections.

A. Assessments for determining water availability and acceptance for new buildings and/or issuance of permits for installation of on-site sewage disposal systems for new residences includes the following:

1. SHD approval of “Application for an Individual Water Supply Site Inspection.” Site criteria as established in Chapter 173-160 WAC and Chapters 4.25 through 4.40 SHDC and SHDC Title 5.

2. SHD approval of “Request for Review: Individual Water Supply” including the following minimum submittals:

a. Signed declaration of applicant;

b. Copy of water well report (well drillers log) verifying well construction per Chapter 173-160 WAC;

c. Documentation of well yield testing per WAC 173-160-345(1) sufficient in detail to demonstrate a minimum 400 gallons per day per residential connection;

d. Satisfactory results of a bacteriological analysis; and

e. Satisfactory results of inorganic chemical analyses for the following: arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver, sodium, fluoride, and nitrate.

3. For IWSs consisting of more than one single-family residential connection, the following must be provided in addition to subsections (A)(1) and (A)(2) of this section: recorded declaration of water use agreement(s), easement(s), and restriction(s) including the following minimum information:

a. Identification of the supply as an individual water supply;

b. Description of system management and ownership;

c. Identification of the property or properties served; and

d. Recognition of system restrictions as determined by SHD.

4. For IWSs consisting of more than one single-family residential connection where the structures served do not exist on the same property, the following must be provided in addition to subsections (A)(1), (A)(2) and (A)(3) of this section: SHD approval of “Application for an Individual Water Supply Site Inspection” demonstrating potential well sites on each of the two properties. Site criteria as established in Chapter 173-160 WAC and Chapters 4.25 through 4.40 SHDC and SHDC Title 5.

B. Operational Checks. Assessments of water supply source quality in response to “Request for Report on an Individual Water System” will include SHD testing of water quality parameters as established in subsections (A)(2)(d) and (A)(2)(e) of this section.

C. Well Sealing and Decommissioning. Pursuant to the “Memorandum of Agreement between State of Washington Department of Ecology and Snohomish Health District,” delegating to SHD the authority to administer and enforce the well sealing and decommissioning portions of the water well construction program in accordance with the provisions of Chapter 173-160 WAC, entitled Minimum Standard for Construction and Maintenance of Wells, notification to SHD must be received no less than 24 hours prior to sealing or decommissioning of any new or existing well in Snohomish County.

D. Determining Maximum Contaminant Level (MCL) Violations for an IWS.

1. Coliform bacteria are not to exceed one per 100 milliliters for any sample tested using the membrane filter method; nor are there to be any present using the presence/absence method of testing.

2. The presence of any tested primary contaminant measured above the MCL, as defined in WAC 246-290-310, shall make that water supply initially unacceptable and subject to further sampling and testing to determine whether an MCL violation has occurred.

a. Three samples must be taken at the well. Prior to the taking of each sample, either a quantity of water equal to three well volumes for drilled wells or two well volumes for dug wells, pumped at the well’s measured production rate, must be pumped.

b. The water must be tested for the same contaminant(s) found in excess of the MCL in the initial sample and the results of the three samples will be averaged. The average of these three sample results will be used to determine if an MCL violation has occurred. If any single sample exceeds double the MCL, then the violation will be considered confirmed.

c. At least one of the three samples must be collected by SHD personnel.

d. No two samples used for averaging may be collected on the same day. There shall be a minimum of 15 days between collection of the first and third samples used for averaging.

E. Water Treatment. Pursuant to these supplemental procedures, as well as other guidelines presently in effect, when evaluating test results for primary contaminants, the MCLs cannot be exceeded and be in compliance with RCW 19.27.097 as a potable water supply. However, RCW 19.27.097 and the Department of Ecology (DOE) guidelines have not provided specifics on the issue of treatment of such water to be in compliance with RCW 19.27.097. Therefore, for the sake of consistency in the evaluation by SHD and to provide commonality of standards for applicants, as well as standards by which the county can consider the recommendations of the SHD relative to the same, the following constitute what the SHD considers to be minimum acceptable standards for source treatment where primary contaminants exceeding MCLs are confirmed:

The SHD shall provide to the county a recommendation of general compliance to the DOE guidelines and these procedures, even when test results for primary contaminants exceed the MCLs; provided, that an applicant has demonstrated satisfactory treatment and provided the following conditions have been or shall be met:

1. Water treatment must be installed at or before the point of entry and provide for whole house treatment.

2. Point of use treatment devices shall not be considered to satisfy the requirements of these procedures.

3. The treatment system must be capable of producing a minimum of 400 gallons of treated water per residential connection per day. However, a daily volume of less than 400 gallons per residential connection may be considered adequate if such a reduced volume is combined with appropriate conservation or storage measures rendering the additional volume unnecessary. The treatment system plan shall not allow the plumbing arrangement to bypass the treatment system.

4. Treatment proposals shall be designed by a state of Washington licensed professional engineer and shall at a minimum include:

a. Expected yield of treated water.

b. Locations at which treated water will be supplied.

c. Other water quality parameters considered in the design of the treatment process.

d. Minimum operation and maintenance requirements for the treatment process.

e. Method of treatment process residuals management.

f. Minimum ongoing testing requirements.

5. The applicant/property owner, prior to issuance of county building permit, is required to record with the Snohomish County Auditor a statement containing the common and legal address of the property, the property legal description and tax parcel number, as well as the present owner’s name and containing, as a minimum, the following additional information:

a. The parameter that is found in the violation of the MCL and being treated for.

b. The concentrations of the parameter that exceeds the established MCL, both before and after treatment.

c. The type of treatment process installed.

d. The expected yield of treated water, expressed in gallons per day.

e. Locations at which treated water is provided.

f. That the treatment device must be properly maintained, along with periodic sampling, to ensure continued safety of the water supply. (Note: Specific sampling frequency is to be set in accord with the designing engineer’s recommendations, with a minimum of no less than once annually.)

g. A stated understanding and acknowledgment, by the property owner, that failure to sample and maintain the treatment system may result in adverse health effects to the users of the water supply and that any untreated water is considered unsafe for consumption.

h. The owner’s obligation and responsibility to notify future property owners, heirs, successors, or tenants about the treatment device, proper maintenance and operations, sampling requirements, potential health risks, and most recent sample results of the water supply both before and after treatment.

i. That the SHD may conduct a site visit within the first two years of occupancy for the purpose of collecting a sample of the treated water for analysis and to provide owner/occupant education relating to individual water supplies.

6. SHD will charge fees for records maintenance, follow-up water testing, and owner education activities as set forth by the Board of Health in the current fee schedule.

7. All proposals for water treatment must be reviewed by SHD for consistency with these policies and procedures. Furthermore, the applicant shall execute a statement which provides that any such review shall not constitute an endorsement by SHD that such a treatment system in fact works, is reliable, or otherwise warranted or guaranteed to effectively treat the water to eliminate all health risks. In all respects, the applicant assumes full and complete responsibility and liability relative to the effectiveness, reliability and viability of a water treatment system.

F. Lead Levels. Pursuant to these supplemental procedures, as well as other guidelines presently in effect, when evaluating test results for contaminants, in the absence of an established MCL, the following evaluation procedure for lead levels in drinking water applies:

1. SHD, in determining potability for compliance with the assessment procedures outlined in subsections (A) and (B) of this section, will apply the EPA “Action Level” of 0.015 mg/l.

2. For results in excess of 0.015 mg/l, the applicant is required to conduct additional testing to demonstrate that the source water is of adequate quality with lead levels less than 0.015 mg/l.

G. Fluoride Levels. Pursuant to these supplemental procedures, as well as other guidelines presently in effect, when evaluating test results for contaminants, the primary MCL of 4.0 mg/l for fluoride cannot be exceeded and be in compliance with the potability requirements outlined in subsections (A) and (B) of this section. For results in excess of 4.0 mg/l, subsections (D) and (E) of this section will apply. For fluoride analyses with results less than or equal to 4.0 mg/l and greater than 2.0 mg/l, the following evaluation procedures apply:

1. The procedures outlined in subsection (D) of this section will apply to determine the level.

2. Upon confirmation of the level as being within the 2.0 mg/l to 4.0 mg/l range, written notification will be sent to the applicant outlining the test results with attached toxics fact sheet for fluoride. Additionally, the notification will direct the applicant to sample quarterly for a two-year period to confirm stability of levels with reduced sampling frequency of one per year if stable within the 2.0 mg/l to 4.0 mg/l range.

3. The owner/applicant must notify future owners, heirs, successors, or tenants of the presence of fluoride in the drinking water and record the notification letter outlined in subsection (G)(2) of this section on the title of the property.

H. Arsenic Levels. Pursuant to these supplemental procedures, as well as other guidelines presently in effect, when evaluating test results for contaminants, the following additional procedures for arsenic apply:

1. For the purpose of these “Supplemental Drinking Water Policies and Procedures” the MCL for arsenic shall be 0.010 mg/l (10 parts per billion [ppb]).

2. For the purpose of satisfying subsection (E) of this section, treatment will only be considered for contaminant levels less than or equal to 0.150 mg/l (150 ppb).

3. For arsenic levels greater than 10 ppb and less than or equal to 50 ppb, compliance with subsection (E)(5) of this section is required prior to SHD acceptance of the on-site sewage system “as-built” drawing for the structure to be served with treated water.

4. Subsections (E)(1), (E)(2) and (E)(3) of this section do not apply to arsenic levels less than or equal to 50 ppb.

5. In addition to the requirements listed in subsection (E) of this section, for individual water supplies with treatment to remove arsenic, the following U.S. Environmental Protection Agency “Health Effects Statement” shall be recorded onto the property title:

Some people who drink water containing arsenic in excess of the MCL over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer. (40 CFR 141.154(f) and 141.153(d)(6)).

6. For individual water supplies with arsenic detected at or below the MCL, a statement must be recorded onto the property title prior to issuance of building permit, containing at a minimum the following:

a. The results of each known arsenic analysis as well as any average used to determine compliance with the MCL.

b. That arsenic concentrations in groundwater can vary over time.

c. That there is variability in laboratory reporting.

d. The following U.S. Environmental Protection Agency (EPA) “Informational Statement”:

While your drinking water meets EPA’s standard for arsenic, it does contain low levels of arsenic. EPA’s standard balances the current understanding of arsenic’s possible health effects against the costs of removing arsenic from drinking water. EPA continues to research the health effects of low levels of arsenic which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems. (40 CFR 141.154(b)(1)).

7. When averaging samples per subsection (D)(2) of this section, if any single sample exceeds 0.050 mg/L (50 ppb) arsenic then the MCL violation will be considered confirmed. Averaging per subsection (D)(2) of this section may be completed to determine the type of treatment required. [Res. 02-13. Revised 02/09/98. Res. 96-13 § 3. Prior code § 9.1 (Attachment) (IV)].