The water situation

TL;DR

The facts on file

• Three wells — and all three now have test history. Jerry & Don's records (received 2026-07-06) add seven historical well tests (2000–2014) and the primary's DWR completion report to the one certified test the disclosure packet held.
• The primary is proven across two decades: est. 8 GPM at drilling (2002), 7.3 GPM (2003), 8 GPM (2006), 10.6 GPM stabilized (2014), and the conservative 4.0 GPM certified with 100% recovery (2021). Static level 17–50 ft in every test since 2003.
• The 168-ft "Weeks" well is the sleeper: 10 GPM (Weeks Drilling, 2000) and 11.5 GPM (Jerry & Don's, 2001) — the best numbers on the property. It may be the well the system map marks "not in use."
• The ~100-ft steel well is weak: 2.5 GPM (2000), 1.85 GPM (2001) — producing sand at 70 ft, with obstructions in the casing. It appears to be the "olive tree" well trickle-feeding the houses' pressure system.
• Water quality has real data now (2014 panel): TDS 160, nitrate 0, iron 0.2, pH 7.6 — clean minerals — but hardness 27 gpg (very hard) and a recurring sulfur smell on the primary. Bacteria, arsenic and boron were sampled repeatedly (2000, 2001, 2006, 2014) but those lab results never made the file.
• ~40,000+ gal of storage. Working figure from J&D: 40,000 gal (2× 10,000 concrete + 4× 5,000 steel). The hand-drawn system map shows a third 10,000-gal concrete plus a 4,000-gal tank at the wellhead — the inventory needs reconciling.
• The aquifer is healthy. A hydrogeologic study placed it in a Class 2 major-recharge zone — ~11,933 ac-ft stored, ~247 ac-ft/yr recharge — with no overdraft and no impact to neighboring wells, and judged even a heavy modeled draw (~2.3 ac-ft/yr) sustainable. Current ag use is only ~0.66 ac-ft/yr.
• Clean history. No dry-well events, no water-supply restrictions, and no disclosed defects in the wells or plumbing.

What we can reasonably conclude

• The capacity question now has a likely answer. If the two backup wells still perform anywhere near their 2000–01 numbers, combined instantaneous capacity is roughly 16–24 GPM — several times the one-well picture the certified test alone painted. The question has shifted from "is there capacity?" to "does 25-year-old performance still hold?" — exactly what the J&D re-test will answer.
• The certified 4.0 GPM under-sells the primary. That test drew the well down only 40 ft; the tests that pulled 150–200+ ft of drawdown sustained 7.3–10.6 GPM. The practical limiter when pumping hard is sand/turbidity, not the aquifer.
• Quality is workable, not pristine. For irrigation the minerals are genuinely good (TDS 160, nitrate 0). Hardness (27 gpg) and sulfur are domestic-comfort/treatment issues — and the seller's own infrastructure plans already plumb softened water to the cabin compound. The ag-critical unknown left is boron (sampled three times; results never in the file).
• Net: upgraded from "promising but unproven" to promising with a documented 25-year history. Verify current performance and close the quality gaps before waiving a contingency.

If we make an offer — water contingencies & inspections

• Put a water/well contingency on any offer. Make it explicit: the right to test all three wells, with a minimum-yield threshold and acceptable water-quality results you define, and a walk-or-renegotiate right if they aren't met.
• Call Jerry & Don's first — done, and it paid off. In motion Ben Campanile went through their records and sent (2026-07-06) everything on this page marked new: the old well tests, the 2002 completion report, and the system schematics. Nathan Emschweiler — their well tester — is quoting cost & timing for a current yield test of all three wells (goal: combined yield/recharge, excluding the storage assist). The water-quality test was deferred for now (our 2026-07-06 email); it goes back on the list before close.
• Chase the missing lab pages with Ben. The 2000 Weeks tests attached bacteriological + mineral/nitrate/boron analyses; Jim Mickelson's 2006 letter promised sample results "shortly"; the 2014 test took arsenic and coliform/E. coli samples. If those pages are still in the file, they're free data — ask.
• Key the system map to the wells with Nathan. Which physical well is "not in use"? If it's the strong 168-ft Weeks well, what would recommissioning take (its pressure tank was already bad in 2001)? And confirm the real tank inventory — 2× vs 3× 10,000-gal concrete, the 4,000-gal wellhead tank, and the steel-bank sizes.
• Test before close, under the contingency. The 3-well yield test (in motion above — ideally late dry-season); a full potability + ag-suitability panel (coliform / E. coli, nitrate, arsenic, boron, EC/salinity, SAR, pH, hardness); and pull the DWR well-completion reports for the two older wells — the 2002 primary's (№ 807042) is now in hand.
• Get the full hydrogeologic report. The study below is only summarized in the permit file — request the original (Hurvitz Environmental, 2022) for its well-interference and drawdown detail.
• If the ag vision is irrigation-intensive, add a hydrogeologist / ag-well consult to size wells and storage to the actual plan before committing.

Who inspected the wells

The disclosure packet held one formal well inspection — the 2021 yield-certification pump test on the primary (filed as Permit Sonoma's WLS-010 form + Jerry & Don's Well Test Report #1493, commissioned for the prior owner's cannabis application). The service file Jerry & Don's sent on 2026-07-06 shows the real depth of the record: 25 years of professional well work — Weeks Drilling & Pump tested both older wells in 2000, Jerry & Don's tested wells in 2001 (×2), 2003, 2006, 2014 and 2021, and Fisch Bros. Drilling drilled (and completion-reported) the primary in 2002.

The certified test

Jacob Emschweiler (field technician, California Lic. C-57 #424778), approved by Jim Mickelson — test 2021-09-08 (report #1493), filed to Permit Sonoma 2021-09-30, commissioned by Mike Agins (owner / Bloomfield Farms, LLC)

Company

Jerry & Don's Yager Pump & Well — 1290 Bodega Ave, Petaluma, CA 94952 · (707) 762-1473 · Lic. C-36 / C-57 424778

Also in the file

Weeks Drilling & Pump Co. (Sebastopol) — 2000 tests of both older wells · Fisch Bros. Drilling (Sebastopol) — drilled the primary, 2002, DWR completion report № 807042

The incumbent

Jerry & Don's services the wells and pumps bi-annually — and their institutional memory goes back to 2001

Engaged now

Ben Campanile sent the historical records (2026-07-06); Nathan Emschweiler — who runs their well inspections and yield tests — is quoting a current 3-well yield test In motion

Sources: Well Documents — WLS-010 Certification + Well Test Report #1493 (5 pp); Jerry & Don's service-file records (10 pp, received 2026-07-06). Servicing arrangement confirmed in the Seller Property Questionnaire.

The certified well — Wel 21-0414 · the 5″ PVC well

This is the site's primary domestic/irrigation well, near the southwest corner of the parcel — the well Ben's records call "the 5″ PVC well drilled in 2002." Here's what the 2021 certification test measured.

How it's built — DWR completion report № 807042 New

Drilled

Aug 2–6, 2002 · Fisch Bros. Drilling (Sebastopol) · rotary-air · Permit Sonoma WEL01-0544 (issued 2001-09-21) · planned use: domestic water

Bore / casing

300-ft boring, completed at 297 ft · 5″ F480 PVC · 10″ bore to 30 ft, 7½″ below

Screen & seal

Perforated 160–297 ft (1/32″ slots) · gravel filter pack 30–297 ft · bentonite sanitary seal 0–30 ft

Geology

Sandy clays to ~45 ft → sandstone 45–70 ft → sandstone w/ shale 70–250 ft (the producing zone) → shale 250–300 ft

At completion

Airlift estimate 8 GPM over 4 hr, 220 ft total drawdown · static 140 ft (measured Aug 6, 2002, days after drilling — every later test found 17–50 ft)

Every test of this well on record

How to read the spread — 4.0 vs 10.6 GPM. The certified 2021 test drew the well down only 40 ft and held 4.0 GPM with full recovery — a conservative, compliance-grade number. The 2003–2014 tests pulled the level down 150–200+ ft (the pump sits at 280 ft) and sustained 7.3–10.6 GPM. So deliverable yield depends on how hard you pull: with static at 17–50 ft there's roughly 200 ft of working drawdown above the pump, and the practical ceiling is sand and turbidity when pumped hard (J&D throttled it in 2003 for exactly that), not the certified 4.0. Storage buffers the rest: current ag use (~0.66 ac-ft/yr ≈ 590 gal/day) is a few hours of pumping a day even at 4 GPM. The low specific capacity (~0.04–0.1 gpm/ft across tests) is typical of west-Sonoma bedrock wells. The recurring sulfur smell and trace sand are quality/maintenance notes, not yield problems — see Water quality below.

Sources: Well Documents — WLS-010 form (p. 1), pump-test data log (p. 2), Well Test Report #1493 (pp. 4–5); Jerry & Don's service-file records — DWR completion report № 807042 (p. 1), 2003 test (p. 6), 2006 draft test + cover letter (pp. 4–5), 2014 test #1024 (pp. 9–10).

Water tanks & storage

The storage picture is much clearer now — the hand-drawn system map in Jerry & Don's file shows the whole tank-and-booster chain — but the counts across sources still don't fully agree:

Working figure

~40,000 gal — 2× 10,000-gal concrete + 4× 5,000-gal steel (our current understanding, confirmed to J&D in the 2026-07-06 email)

The system map shows

Possibly more: three 10,000-gal concrete tanks, a 4,000-gal concrete at the primary wellhead, and the bank of 4 steel tanks (sizes unlabeled) Reconcile

Earlier records

Seller amenities claimed ~45,000 gal; the 2021 test report recorded "(4) × 5,000-gal concrete" — almost certainly the steel bank, mis-recorded

Pressure tanks on record

WX-201 @ 130 psi (primary, 2021) · WF-260 85-gal @ 50–70 psi (2014) · WX250 (old steel well, 2000) · 300-gal galvanized — "bad, leaks on the side" (168-ft well, 2001) · old 315-gal riveted (2000)

Other water infra

A storm-water retention pond + drainage, from the prior site-prep work

How the water moves (per the system map New): the primary well fills a 4,000-gal concrete tank at the wellhead on a float switch; a booster pushes water up the hill to the bank of 4 steel tanks and a mid-property 10,000-gal concrete (solenoid fill, its own booster), and onward to an upper 10,000-gal concrete with a Cla-Val float valve that gravity-feeds the cottages' own 10,000-gal tank and the horse-barn line (that barn booster is marked "not in use"). Separately, the "olive tree" well (8″ steel, ½-hp submersible — the weak one) runs the houses' pressure system. One well on the map is flagged "well — NOT IN USE."

Storage is doing real work here. Gravity plus boosters plus ~40k gal of buffer is exactly the right architecture for low-yield bedrock wells — the tanks convert a trickle into usable peak flow. It also means tank condition and the true inventory matter: confirm counts, sizes and serviceability with Nathan during the yield test; for an intensive ag plan, expanded storage remains one of the cheaper ways to stretch these wells.

Where the four tanks sit matters. The Transfer Disclosure (§C.7) reports that soil can slump on the west-side slope "below the 4 water tanks" during extreme rain — it's happened "a few times in 24 years," each time cleared with a tractor and the perimeter road rebuilt. So the concrete-tank pad sits above a known, minor, recurring slump zone. Combined with §C.6 (the pad sits on extensive select fill over a former quarry floor), the west-side ground near the storage warrants a geotech look before relying on or expanding that pad.

Sources: Water-system schematics + hand-drawn system maps (received 2026-07-06 — tanks, boosters, gravity feed, "well not in use"); Seller list of Amenities (~45,000 gal, 3 wells); Well Test Report #1493 (the "4 × 5,000-gal concrete" tanks, p. 4); Transfer Disclosure (TDS) §C.6 (fill) and §C.7 (slump below the 4 tanks).

The three wells

The parcel has three active wells (confirmed in the seller's amenities list and the hydrogeologic study). The service file finally puts numbers on all three — with the caveat that the two backups were last tested 25 years ago:

Well identities are keyed by casing size + depth across the records and the system map — solid for the primary; confirm the two backups with Nathan during the re-test, including which one is the idle well. The backup numbers are 2000–01 vintage and need re-proving; the 168-ft well's DWR completion report (Weeks drilled it) and the old well's are still worth pulling. Sources: service-file records (Weeks tests pp. 7–8; J&D 2001 tests pp. 2–3); Seller list of Amenities; hydrogeologic study (in the permit Initial Study / MND).

Water quality — the first real data New

Until this file arrived, the record held zero water-quality data. Now there's a real mineral panel — run by Jerry & Don's on the primary well during the 2014 test — plus quality field-notes across two decades. Verdict: good irrigation water, needs treatment for domestic comfort, one important ag number still missing.

The field notes agree with the chemistry. The primary's water had a sulfur (H₂S) smell in 2003 ("cloudy… sulfur smell") and 2006 ("strong sulfur smell") and pulls trace sand when pumped hard — nuisance/treatment issues common in shale-influenced bedrock wells, not health findings. The old steel well's 2001 test flagged sodium for sampling. And the seller's own engineers designed around all of this: the Carlile Macy infrastructure plan plumbs softened water to every building in the cabin compound, and its margin notes spec a Fleck-valve softener, calcite, UV and R.O. — i.e., hard, sulfurous well water was a known, managed condition here.

What this means: for irrigation, TDS 160 / nitrate 0 water is better than much of west Sonoma — pending the boron number. For a future residence, budget a treatment train (softener ± sulfur oxidation ± UV; R.O. at taps) — a solved, few-thousand-dollar problem, not a red flag. The real gap is paperwork: get the 2014 arsenic/bacteria results and any 2000/2001/2006 lab pages from Ben, and run the full potability + ag panel before close.

Sources: service-file records — 2014 panel (p. 10), sulfur/sand comments (pp. 5–6), sample flags on the 2000–01 tests (pp. 2–3, 7–8); system schematics — softened-water plumbing + treatment notes.

Basin & aquifer capacity

The prior owner's permit work left behind one genuinely useful asset: a basin-wide hydrogeologic study (Hurvitz Environmental, 2022). Its conclusions are about the aquifer, so they hold regardless of what the land is used for — and they're reassuring on the question of whether the resource can support a serious ag draw.

Groundwater setting

Sonoma County Groundwater Availability Class 2 (Major natural recharge); not a priority basin; "very low priority" under SGMA

Aquifer storage

~11,933 acre-ft stored in the study area

Annual recharge

~247 acre-ft/yr (≈123.5 ac-ft in drought years)

Current onsite use

~0.66 acre-ft/yr (horses + landscaping today)

Heaviest modeled draw

~1.27 ac-ft/yr net (the study even modeled a full cultivation operation on top of existing ag) — still well under 1% of recharge

Verdict

Sustainable — no overdraft, and no significant impact to neighboring wells or streamflow

What this means for an ag project. At the resource level there's ample headroom — current use is a rounding error against annual recharge, and even a far heavier draw was judged sustainable with no overdraft and no harm to neighbors. So the basin is a green light. The limiter is purely on-site: how much you can physically extract and store. Scaling water for serious ag here is an infrastructure question (wells + storage), not a question of whether the water is in the ground.

Source: Hydrogeologic study, summarized in the CEQA Initial Study / MND — water-supply narrative and Table 4 (p. 52). The underlying report (Hurvitz Environmental Services, 2022-01-26) isn't in the packet; request it from the listing agent for the full well-interference and drawdown analysis.

Where the water stands today

As it runs now: the wells and ~40,000+ gal of storage have supported a commercial vegetable farm, a horse-boarding operation, livestock and landscaping for years on roughly 0.66 acre-ft/yr of groundwater, with the certified primary at 4.0 GPM / 100% recovery. The seller discloses no dry-well history (no county drought-tank assistance), no water intrusion, no defects in the well or plumbing, and no restrictions or surcharges on the wells or groundwater. For the current level of use, the water has been sufficient and uneventful.

For a future residence: the same wells should comfortably serve a modest house alongside continued ag use — the binding constraints are storage and treatment (hard water + sulfur are documented; bacteria/arsenic results still unseen), not flow. Budget the treatment train; confirm potability before you trust it.

For a serious ag operation: this is where it gets real. Whether the property can water an intensive, irrigated ag use comes down to combined deliverable yield across all three wells plus storage — and the file now says that could plausibly be 16–24 GPM (vs. the 4-GPM single-well picture) if the backups still perform like 2000–01. Two-thirds of that is 25-year-old data. The aquifer can supply it; the current J&D re-test is what turns "plausible" into "proven."

Sources: Seller Property Questionnaire (SPQ) §§8–10 (no dry-well assistance, intrusion, or well restrictions); Transfer Disclosure (TDS) (water supply = private well; septic).

Sources: SPQ §10.C; hydrogeologic study / Initial Study (no Class I/II streams on-site; ephemeral Class III drainages only).

Source documents

Every figure on this page traces to one of these — the seller's disclosure packet, the permit-era water studies, and (new) Jerry & Don's service file, mirrored here so you can read the original alongside the finding.