HomeMy WebLinkAboutBLD2025-00825 - BLD CD Environmental Health Review - 7/15/2025 ut No
MASON COUNTY
�' '' �` COMMUNITY DEVELOPMENT
PemP)k'11 � "/`V�vPermit Assistance Center, Building, Planning
PLUMBING & MECHANICAL PERMIT APPLICATION 70 m r It
OWNER INFORMATION: CONTRACTOR INFORMATION: n 0'
NAME:William H.Gates III NAME:Fairbank Constructim Co. rn
MAILING ADDRESS:15120 NE 921d St MAILING ADDRESS:220 Maclson Ave S
CITY: Redmond STATE:WA ZIP:98052 CITY:Bainbridge Island STATE:WA ZI':98110
1St PHONE:425 753-7755 PHONE:206.842.9217 CELL: 206 551.96 i.
Znd PHONE:425-753.7755 DerrickMlniken,Owner Representative EMAIL :colin@rairbankcrostructim.com
EMAIL: derrick miniken@gateswnttrescorn L&I REG#FA1RBce183c2 EXP. 06 /25 /26
PARCEL INFORMATION:
PARCEL NUMBER(12 agit lumber):32233-50-00011 Zoning.RC2
LEGAL DESCRIPTION(Abbreviated):SUNNY BEACH PCL 1 OF BLA#04-57&T.L.
SITE ADDRESS:6999E STATE ROUTE 106 CITY:UNION
DIRECTIONS TO SITE ADDRESS:
Travel East from Union on Highway 106, property on left just before Alderbrook Resort
TYPE OF JOB:
NEW t]ADEI I ALT) ✓ II REPAIRI 1 OTHE USE OF BUILDING Residence
LOCATION OF FIXTURES/UNITS—1sT FLOG•MN 2ND FLOO/ZM BASEMENT GARAGE OTI-tERf1
PLUMBING FIXTURES(SHOW NUMBER OF EACH) MECHANICAL UNITS
Type of Fixture No. of Fixtures Fees Fuel Type:ElectricLPCc 1Natural Ga.4-1Ductles4-1
Toilets 2 18.00 Type of Unit No. of Units Fees
Bathroom Sink 2 18.00 Furnace
Bath Tubs 2 18.00 Heat Pump
Showers Spot Vent Fan 1 to 00
Water Heater 3 2700 Propane Tank
Clothes Washer Gas Outlets
Kitchen Sinks Wood/Gas/Pellet Stove
Dishwasher Kitchen Exhaust Hood
Hose bibs Dryer Vent
Other Solar Panel
Other
Base Fee 25.00 Base Fee 30.00
TOTAL PLUMBING 106.00 TOTAL MECHANICAL 40.00
OWNER acknowledge submission of Inaccurate Information may result in a stop work order or permit revocation.Acknowledgement of such Is
by signature below.I declare that I am the owner,owners legal representative,or contractor.I further declare that I am entitled to receive this
permit and to do the work as proposed.I have obtained permission from all the necessary parties,including any easement holder or parties of
Interest regarding this project.The owner or authorized agent represents that the information provided is accurate and grants employees of
Mason County access to the above described property and structure(s)for review and Inspection.This permit application becomes null&void
If work or authorized construction Is not commenced within 180 days or If construction work Is suspended for a period of 180 days. PROOF
OF CONTINUATION OFTHIS PERMIT IS BY MEANS OF INSPECTION.INACTIVITY OF THIS PERMIT APPLICATION OF 180 DAYS
WILL INV DATE T APPUC .
X � f/L-c. ' 0-77Z
Signature of Owner Da
DEPARTMENTAL REVIEW APPROVED D�T'tr)p RI)1��// FIFE TAGS/NOTES/CONDITIONS
BUILDING DEPARTMENT ��{{ V
PLANNING DEPARTMENT SEP 11 2U25 AD 5 j ' pi c&V1
FIRE MARSHAL MASON COUNTY ENVIRONYD TAL NEALT 7 -no CkpV1rii -
RET
Rev: 1/27/2016 JBN N 0
March 28'h, 2025
Rhonda Thompson, RS
Environmental Health Specialist
Mason County Public Health
415 N. 6'h St.
Shelton, WA 98584
RE: Hood Canal — Union Residences — Community OSS; Parcel No. 322335000011
SU: Community Drainfield Capacity
Dear Rhonda,
Regarding the property parcel listed above, this letter and its enclosures present a
review of the capacity of the community on-site sewage system (OSS) aerobic treatment
unit (ATU) and drainfield and the desire to reclassify the permitted maximum number of
bedrooms that can be accommodated by the community OSS.
4
SUMMARY OF REQUEST
To first summarize the request, the community OSS has a permitted maximum daily flow
of 3,060 GPD, based on the 2005 design and subsequent approval by Mason County
(see enclosed community OSS design and record drawing file, also filed under Parcel
No. 322335000011). This maximum daily flow was based on a design for 17 bedrooms
at a "daily flow" of 120 GPD/bedroom, or 2,040 GPD, multiplied by a second peaking
factor of 1.5 for a permitted maximum daily flow of 3,060 GPD. It is not understood why
a second peaking factor of 1.5 was applied to the initial design flow, as the 120
GPD/bedroom design flow already uses a peaking factor of 1.33, as described in WAC
246-272A-0230— Design Requirements - General. Based on the permitted maximum
daily flow of 3,060 GPD, along with several other supporting factors discussed in this
letter, we would like to reclassify the maximum permitted number of bedrooms to 25.5
([25.5 bedrooms] x [120 GPD/bedroom] = 3,060 GPD).
DETAILED NARRATIVE OF REQUEST
The current community OSS, including the aerobic treatment unit (ATU) and drainfield,
was approved by Mason County in February 2007 (design approval letter from Cathy
Waite dated February 28'h, 2007) for a maximum day flow of 3,060 GPD, at a maximum
soil hydraulic loading rate of 1.0 gallons per day per square foot (GPD/FT2)for the
former Washington State Type 2A soil classification. To achieve the 3,060 FT2 of
drainfield trench bottom area, 12 laterals, each 85 FT long and 3 FT wide were
constructed (totaling exactly 3,060 FT2).
The ATU is an OrencoV AdvanTex®single-pod AX-100 system and has an "operating
capacity" (i.e. long-term, sustained) design flow of 2,500 GPD, and a maximum day
design flow of 5,000 GPD, when the "influent" to the AdvanTex®treatment system is
equal to or less than Washington State's Treatment Level E (i.e. typical residential
Aqueous Solutions Engineering,/'LLC' Ph:(360)318-4704 Em: mike.moren75@gmail.com
P.O. Box 1635
Bellingham, WA 98227 Page 1 of 5
Hood Canal-Union Residences
Community OSS Capacity Re-allocation Request
March 28'h, 2025
strength septic tank effluent); or on a mass load basis, up to four (4) pounds of BOD5 (5-
day biochemical oxygen demand) per day, sustained.
The AdvanTee treatment system is a Washington State Treatment Level "C"-registered
ATU.
The final permitted Design Flow of 3,060 GPD for the community OSS was derived from
a design flow of 2,040 GPD based on a total of 17 bedrooms (17 bedrooms times 120
GPD/bedroom design flow), multiplied by a second "LOSS" (Large On-site Sewage
System) peaking factor of 1.5 ([2,040 GPD] x [1.5] = 3,060 GPD).
It is not clear why a second peaking factor was applied. Washington State's design flow
of 120 GPD/bedroom already includes a 1.33 peaking factor, as presented in WAC 246-
272A-0230 Design Requirements— General:
(2) The designer shall use the following criteria when developing a design
for an OSS:
(d) The OSS is designed to treat and disperse the sewage volume as
follows:
(i) For single-family residences:
(A) The operating capacity is based on 45 gpd per capita with
two people per bedroom.
(B) The minimum design flow per bedroom per day is the
operating capacity of ninety gallons multiplied by 1.33.
This results in a minimum design flow of one hundred
twenty gallons per bedroom per day.
It should be noted that this WAC chapter language was filed 7/18/2005, and became
effective 7/1/2007. The original community OSS design application was submitted on or
around May 4'h, 2005, underwent some changes during the County review process, and
was ultimately approved by Mason County in a letter dated February 28'h, 2007. The
Code language above is also consistent with the upcoming WAC 246-272A revision that
will become effective on 4/1/2025.
Mason County Public Health On-site Standards also does not require a second peaking
factor placed on the 120 GPD/bedroom.
The Mason County's On-site Standards do have the following requirements for OSS with
design flows greater than 2,000 GPD and less than 3,500 GPD:
• Pressure distribution.
• Annual operation and maintenance.
• All of the Recommended Standards and Guidance for pressure distribution must
be followed. The required drainfield area shall be split into two 50 percent
drainfields. A third 50 percent drainfield shall be constructed initially in order to
provide for alternation (long term resting). A reserve area equal to an additional
50 percent is required. Where facilities have an automatic resting cycle like a
campground, the requirement for three 50 percent drainfields may not be
necessary. A 100 percent reserve is required when a third 50 percent drainfield
is not required.
Aqueous Solutions Engineering,PLLC P.O. Box 1635 Bellingham,WA 98227
(360)318-4704
mike.moren75(a gmail.com Page 2 of 5
Hood Canal-Union Residences
Community OSS Capacity Re-allocation Request
March 28', 2025
The community OSS meets all of these requirements. For the drainfield reserve area, a
reserve area equal to 100% of the primary drainfield area is set aside. The existing
lateral trenches have a 9-FT. on-center spacing, and the reserve trenches are located
between the built trenches, as shown in the 2025 Record Drawings recently submitted to
Mason County Public Health.
As stated in the third bullet on the previous page:
"Where facilities have an automatic resting cycle, the requirement for
three 50% (constructed) drainfields may not be necessary. A 100 percent
reserve area is required when a third 50 percent drainfield is not
required."
The family compound really only sees use primarily from Memorial Day weekend
through Labor Day weekend, and even with that, use isn't constant during this time
period. Outside of this primary use period, only a few year-round staff generate
wastewater to the community OSS, and this is just during a typical 8-to 9-hour work day.
For any contracting work done on site during the "off-season", contractors utilized
temporary portable toilets; they do not use the community OSS. Therefore, with these
use patterns, the community OSS has a built-in resting cycle from moderate to high use
that lasts almost nine months.
Based on the Washington State design flow of 120 GPD/bedroom, and an approved
overall design flow of 3,060 GPD for the community OSS, and as stated in the initial
"Summary of Request" section of this letter, we would like to reclassify the total
number of bedrooms allowed for this community OSS to be 25.5 bedrooms ([25.5
bedrooms] x [120 GPD/bedroom] = 3,060 GPD.
To further support this request, I will present a list of measures that have recently been
done to the community OSS over the last three years to ensure that it is in excellent
working condition.
SUMMARY OF DETAILED OSS EVALUATION, REPAIRS/MODIFICATIONS, AND
DOCUMENTATION
I was retained by the property owner/management entity in early 2021 to evaluate an
"off-season" (fall/winter) high-flow condition due to a documented I&I (infiltration & inflow)
condition of a significant groundwater infiltration leak into a deep septic tank serving one
of beachfront buildings. The project evolved into a detailed evaluation of the community
OSS drainfield, most of the septic & pump tanks, the effluent sewer mains, and the
AdvanTex°ATU, and subsequent repairs & modifications of the community OSS. The
evaluations and repairs & modifications are summarized below and on the following
pages.
COMMUNITY DRAINFIELD
Due to excessive "off-season" I&I flows, coupled with spongy sod in the greater
drainfield area, a thorough investigation of the drainfield was performed. A few soil test
holes were excavated within and adjacent to the drainfield. It was discovered that the
Aqueous Solutions Engineering, PEE(' P.O.Box 1635 Bellingham,WA 98227
(360)318-4704
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Hood Canal-Union Residences
Community OSS Capacity Re-allocation Request
March 28th, 2025
cover soil was of poor quality with poor drainage characteristics, and that the sod also
had a high silt & clay content, acting like a sponge in retaining rainwater. It was also
discovered that there was absolutely no ponding in the drainfield trenches, nor was there
any signs of anaerobic conditions in the drainfield gravel, and that the soils within the
vertical separation below the drainfield trenches were course gravelly sands consistent
with the 2005 soil assessment. A deep curtain drain was also confirmed to be installed
upgradient from the drainfield. The actual drainfield lateral trenches were found to be in
excellent condition with no signs of hydraulic or organic overloading, despite the
excessive I&I flows during the "wet season". I designed a major drainfield repair to fully
replace the sod & cover soil down to the filter fabric with a sandy cover soil & sod, and
Danos Septic did the repair/modification work in the late winter& spring of 2023. Danos
Septic also performed lateral hydro-jetting in the spring of 2023 and again in the fall of
2024. I, along with Danos Septic, conducted a detailed post-construction inspection of
the drainfield in the spring, and then again in the fall, of 2024, making sure the drainfield
had balanced flow distribution, and that the drainfield dose tank pumping system and
drainfield were in top working condition.
COMMUNITY OSS EFFLUENT SEWER MAINS
Danos Septic conducted a video inspection of the existing gravity effluent sewer mains
in late summer& early fall of 2023 and found them to be in good condition, with no visual
signs of I&I or broken pipe or joints. Based on this, a decision was made to continue
using the existing gravity effluent sewer conveyance system.
INDIVIDUAL BUILDING SEPTC & PUMP TANKS
During the late summer and early fall of 2023, Danos Septic performed tank water-
tightness testing on a majority of the existing septic and pump tanks in the community
OSS and found that some tanks should be replaced, some could be repaired, while
some were in good water-tight condition as-is. Subsequently, in the fall/winter/spring of
2023/2024, the community OSS repair/modification project continued, with Danos Septic
replacing or repairing most of the septic & pump tanks. In addition, other improvements
were made including adding septic tank effluent filters, and new pumping systems and
control panels where needed. Any new tanks were sized to meet Mason County's
current tank sizing criteria.
ORENCO®ADVANTEX®AEROBIC TREATMENT (ATU)
I performed an inspection/evaluation of the Orenco®AdvanTex®AX100 aerobic
treatment system and found it to be in good working condition. There were no signs of
excessive use or overloading. I, working with Danos Septic, performed some standard
O&M, and minor repairs.
UPDATED RECORD DRAWINGS
After the major 2023/2024 repairs/modifications were complete, I prepared a detailed
and comprehensive set of Record Drawings for the entire community OSS. This
updated set of record drawings includes updated tank information (make & model,
installation year [where known], location, size, configuration) for both new and existing
tanks. Pump and control panel make & model information was also included. I also
included updated float level settings, and recommended control panel settings for the
Aqueous Solutions Engineering,PLLC P.O.Box 1635 Bellingham,WA 98227
(360)318-4704
mike.moren75Zvgmail.com Page 4 of 5
•
Hood Canal-Union Residences
Community OSS Capacity Re-allocation Request
March 28th, 2025
AdvanTex°treatment system for both peak season, and "off-season" use, as well as
updated settings for the drainfield dosing system.
CONCLUSION
The community OSS was sized, and constructed, for an ultimate design flow of 3,060
GPD and has an un-constructed reserve area equal to 100% of the design flow. This
design flow will accommodate a total number 25.5 bedrooms, based on the Washington
State (and Mason County) Design (peak day) Flow of 120 GPD per bedroom. The
overall community OSS is in excellent working condition, with absolutely no signs of
excessive hydraulic or organic overloading. I see no reason why the community OSS
could not be re-classified from the original (2005) 17 bedroom capacity, to the requested
25.5 bedroom capacity, as both the constructed drainfield capacity and the ATU were
designed to safely accommodate the Mason County-permitted Design Flow of 3,060
GPD.
It is understood by the property owner, and management entity, that any additional
bedroom requests, beyond the 17 currently approved, may require upsizing of existing
septic and/or pump tanks to meet current Mason County tank sizing requirements, and
that any such request will have to be permitted by Mason County Public Health in
advance of any such work.
Please contact me via phone (360) 318-4704, or e-mail mike.moren75(csgmail.com
should you have any additional comments or questions.
DEL M.
Sincerely, tiG 4,› WAsyf4 O��
s, CEO
Mike Moren, P.E. �o �EG3079 2 '4
sTsW
Aqueous Solutions Engineering, PLLCSSIONALG1
Cc: Bill Hughes, Rhodes Lodge (Watermark Estate Management Services, LLC)
Jim Davidson, Shane McGilvra (James Davidson Architects)
Colin Gilligan, (Fairbank Construction)
Justin Wells, Jon O'Connell (Dano's Septic Tank Pumping)
21
Enclosure:
Community OSS Design, Approval, and As-Built Drawing Documentation (2005-
2007)
Aqueous Solutions Engineering,PLLC P.O.Box 1635 Bellingham,WA 98227
(360)3I8-4704
mike.moren75(a;gmail.com Page 5 of 5