Short answer: identify the exact system first
Do not waive a condition, accept a closing or tenancy handover, or price work from a seller, landlord, map, invoice, or neighbourhood assumption alone. Build one exact-property file that confirms the parcel and service arrangement, then connects approvals, plans, installed components, access, service and emptying records, observations, responsibility, costs, and unresolved professional questions. This checklist does not inspect, approve, diagnose, size, or certify a system.
- Confirm the address, block and parcel, unit, development, current use, proposed use, owner, and operating responsibility before comparing records.
- Ask the Water Authority to confirm central-sewer or onsite status and current process for the exact parcel in writing.
- Keep approved records, installed-condition evidence, service history, and current observations separate; each answers a different question.
- Record who decides each open issue and the deadline before a condition, lease, lender requirement, or handover changes.
Complete the parcel and responsibility screen
Wastewater evidence can sit across an owner, strata, landlord, tenant, developer, supplier, installer, service provider, Planning, and the Water Authority. Start by fixing the property identity and responsibility boundaries so a document from the wrong parcel, unit, development phase, or system is not treated as proof.
| Screen field | Evidence to record | Open question owner |
|---|---|---|
| Property identity | Street address, block and parcel, unit, strata plan, development, phase, and site plan. | Attorney, owner/strata, Lands & Survey, Planning, or Water Authority as relevant. |
| Use and loading facts | Current bedrooms, units, occupancy, rental or commercial use, food service, fixtures, and proposed change. | Owner plus Water Authority and Planning; do not self-calculate approval. |
| Legal and operating responsibility | Registered/strata owner, lease terms, easements, access rights, service contract, emergency authority, and payment owner. | Attorney, strata, landlord, tenant, and property manager. |
| Transaction control | Condition, document request, deadline, extension route, lender or insurer request, and decision-maker. | Buyer/tenant, attorney, lender, insurer, or other named principal. |
Separate central sewer, septic, and ATU evidence
A property can be connected to the central wastewater system or use an onsite arrangement. The Water Authority's public service-area material is useful orientation, but only current written parcel-specific confirmation should close the identity question. If onsite, identify the actual approved and installed system rather than assuming every tank is a septic system.
| Possible arrangement | Evidence file | Do not infer |
|---|---|---|
| Central sewer | Authority parcel/connection confirmation, account or development record, connection drawing, responsibility, and current service status. | Connection from a neighbourhood label, map colour, nearby property, utility bill, or visible pipe. |
| Septic system | Approved two-compartment tank and effluent-disposal-well records, layout, access, service, emptying, inspection, and current observations. | Approval, watertightness, capacity, or condition from a lid, pump-out invoice, or seller statement. |
| Aerobic treatment unit (ATU) | Approved make/model, serial, manual, power, aeration, pumps, alarms, controls, service/O&M reports, disposal route, and open actions. | Performance, certification, service interval, or suitability from the model name or an old approved-system list. |
| Other or unclear arrangement | Plans, Authority/Planning correspondence, installed-condition scope, and written classification or follow-up. | That an unusual component is exempt, acceptable, abandoned, or safe. |
Reconcile approvals, plans, and installed condition
Approved plans and physical inspection answer different questions. Ask which Planning approval, Water Authority review, permit, inspection, completion or occupancy evidence, approved drawing, as-built record, variation, and later alteration record should exist for this property and use. A commercial plumbing submission guide can identify useful drawing fields, but it is not a universal residential code or proof that the installed system matches a plan.
| Record | What it may establish | Reconciliation question |
|---|---|---|
| Planning/Authority approval | Reviewed proposal, use, date, conditions, and responsible parties. | Does it match the exact parcel, phase, use, and latest approved change? |
| Approved plan or as-built | Recorded system type, tank/plant/well size and location, access, separation, and related plumbing. | What did the qualified inspection observe, and who resolves any variance? |
| Inspection/completion evidence | A dated process milestone for stated work. | What was inspected, what was excluded, and were later alterations made? |
| Service or repair record | Work performed, observations, parts, recommendations, and service party at that date. | Does it close an approval, installation, condition, capacity, or follow-up question—or only document one visit? |
Create the component, location, access, and owner register
The file should let the right person locate and safely access each known component without turning the checklist into a technical inspection. Record the approved and observed identities separately, preserve manuals and serial information, and route differences to the appropriate professional.
| Component | Identity and location evidence | Access/power/owner evidence |
|---|---|---|
| Tank or treatment plant | Type, make/model, serial, capacity record, compartments, site-plan location, photos, and covers. | Access route, cover condition note, keys, owner, service authority, and safe-inspection scope. |
| ATU equipment | Aeration/mixing/settling elements, pumps, alarms, controls, panel, and manufacturer manual. | Power source, backup/restart information, alarm contact, O&M provider, and unresolved action. |
| Effluent disposal well | Approved specification/location, installer and licence-at-work evidence, casing/variation record, and access point. | Maintenance owner, obstruction/access note, current concern, and Authority/environmental escalation. |
| Related components | Inlet/outlet, grease interceptor where relevant, plumbing route, sampling point if applicable, and shared-system links. | Cleaning/service responsibility, access rights, affected users, and record custodian. |
Build the septic-system evidence file
Current Water Authority guidance describes a Cayman septic system as a structurally sound, watertight, two-compartment tank discharging to an effluent disposal well. Treat that as the record and inspection question—not a conclusion about this installation. Ask the qualified parties to reconcile construction, compartments, access, inlet/outlet and disposal route, service and emptying history, and current observations.
- Request the approved plan, installation and inspection records, tank and well location, any variation, and later alteration evidence.
- Keep access-cover, surface condition, inlet/outlet, disposal-route, and surrounding-observation notes inside the professional scope that produced them.
- Retain every emptying and service date, company, licence-at-work evidence, scope, volume or disposal record if supplied, observations, recommendations, and completion proof.
- Do not treat one recent pump-out, an absent odour, a seller assurance, or an invoice as proof of watertightness, approval, capacity, or condition.
Build the ATU operating and service file
An aerobic treatment unit is a pre-engineered secondary-treatment system with operating equipment and ongoing management needs. Identify the installed unit and retain the exact current manual, approved record, power and control details, service arrangement, O&M reports, alarm history, readings supplied by the qualified provider, parts, recommendations, and evidence that follow-up work was closed.
| ATU file | Evidence to request | Escalation trigger |
|---|---|---|
| Identity and approval | Make/model/serial, approved proposal, design record, installed location, manual, and variation history. | Identity mismatch, missing approval, changed use, or unavailable current support. |
| Power and controls | Supply, panel, alarm, aeration, pumps, restart/backup information, access, and owner. | Alarm, power loss, unusual noise, damaged control, inaccessible component, or unknown owner. |
| O&M chronology | Visit date, certified technician/provider evidence, scope, observations/readings, parts, solids handling, action, and close-out. | Missed service, repeating issue, open recommendation, inconsistent report, or uncertain current credential. |
Keep a separate disposal-well file
An effluent disposal well is not the septic tank. Water Authority material describes it as a drilled borehole with grouted casing and requires written approval for alternatives or variations; construction and installation fall within a current well-driller licence boundary. Ask for the approved specification and location, installer and licence-at-work evidence, variation approval, access and service history, and qualified follow-up.
- Record the exact well connected to the system, not a nearby well, historic site mark, or generic plan symbol.
- Keep approval, construction, variation, installed-condition, access, and maintenance evidence in separate fields.
- Route standing water, overflow, odour, suspected failure, groundwater concern, or missing records to the Water Authority and appropriately qualified professionals promptly.
- Do not inspect the subsurface, diagnose contamination, interpret a laboratory result, or conclude environmental impact from this checklist.
Build the maintenance, emptying, and follow-up chronology
The Water Authority's owner guide says service frequency depends on system complexity, loading, capacity, and owner observations. Preserve the chronology and ask the current Authority, manufacturer, and qualified provider what interval and scope apply; do not turn general examples or one provider's schedule into a universal rule.
| Date/event | Scope and evidence | Observation/action | Close-out |
|---|---|---|---|
| Routine service/O&M | Provider/technician, current-role evidence, checklist, readings, photos, parts, and report. | Normal, monitored, adjusted, repaired, referred, or unresolved—as written by the provider. | Owner response, invoice, follow-up date, completion proof, and retained report. |
| Septic/cesspool emptying | Actual business, current licence/permit evidence, scope, date, record of removed material/disposal if supplied. | Access, contents/condition observations, issue raised, or no technical conclusion stated. | Receipt/report, recommendation owner, follow-up evidence, and next review source. |
| Alarm, overflow, odour, noise, slow drainage, or outage | First time, duration, affected area, photos/logs, weather/power context, and contacts. | Containment or safety action plus qualified/Authority scope—without template diagnosis. | Written finding, work record, testing if directed, notifications, and lessons/open items. |
Route observations to a qualified scope
An observation starts a question; it does not prove the cause, severity, compliance status, repair, or transaction outcome. Use the log to preserve what was seen or reported, assign the right scope, and stop unresolved issues from disappearing into verbal reassurance.
| Observation or gap | Question—not diagnosis | Possible scope and owner |
|---|---|---|
| Alarm, unusual noise, power loss, or control issue | What equipment/event is involved and what immediate action is safe? | Qualified ATU/O&M or electrical scope, owner, manufacturer, and Authority escalation as appropriate. |
| Overflow, odour, slow drainage, standing water, or suspected discharge | What is the source, affected system, immediate risk, and evidence-preservation need? | Property safety response, qualified wastewater/plumbing scope, Water Authority, environmental or legal advice. |
| Damaged/inaccessible cover or unknown component location | Can the system be safely inspected, operated, serviced, and handed over? | Inspector/service provider, owner/strata, approved-plan review, access-rights and cost owner. |
| Missing approval, service, emptying, or follow-up record | Which current official or professional source can confirm the fact or define the next scope? | Planning, Water Authority, attorney, owner/strata, inspector, qualified provider, lender, or insurer. |
Escalate capacity and change-of-use questions
Current Water Authority guidance uses total estimated parcel flow and a 1,800-gallon-per-day threshold when distinguishing proposed septic and ATU requirements. That number explains why bedrooms, units, occupancy, additions, rental intensity, commercial use, food service, and fixtures matter—but it does not let a household calculate or approve the capacity or suitability of an existing system.
- Write down current approved use, observed use, proposed use, occupancy, bedrooms/units, fixtures, additions, and any food-service or commercial activity.
- Ask the Water Authority and Planning what current records, calculations, applications, upgrades, or approvals are needed for the exact proposal.
- Keep capacity, treatment performance, grease-interceptor, disposal-well, plumbing, Planning, and transaction questions with the discipline that owns them.
- Do not rely on tank size, prior occupancy, an old invoice, no complaints, or a laboratory result as approval for changed use.
Use a written transaction or tenancy handoff
Turn every missing record or unresolved observation into a dated request, professional scope, response, cost/allowance question, condition owner, deadline, extension route, and explicit decision. The buyer, tenant, lender, insurer, owner, or other principal—not this page or a directory provider—decides whether evidence is sufficient for their purpose with appropriate advice.
- List confirmed facts, documents received, installed-condition evidence, current observations, assumptions, and open questions separately.
- Name the exact professional or official scope needed: parcel/service confirmation, records search, legal/access review, property inspection, wastewater O&M, licensed emptying, well work, plumbing, environmental or laboratory advice, lender, or insurer review.
- Record quote or allowance scope, exclusions, currency, tax, access, approvals, uncertainty, expiry, and who carries overruns—without treating an estimate as a diagnosis or final cost.
- Keep extensions, written replies, work evidence, reinspection/follow-up, handover records, and the final principal decision together.
- Do not let a clean inspection, pump-out, service report, or laboratory result substitute for approval, capacity, title/access, installation, or transaction review it was not designed to answer.
Trust note
Last updated August 2026. This guide is written for relocation planning and should be verified with licensed Cayman professionals for legal, tax, immigration, medical, insurance, or financial decisions.
Reference points: Water Authority — Central Wastewater System, Water Authority — Onsite Wastewater Systems, Water Authority — Septic Tanks and Grease Interceptors, Water Authority — Aerobic Treatment Units, Water Authority — Effluent Disposal Well Specifications, Water Authority — Onsite Wastewater Management Programme, Water Authority — Owner's Guide to Onsite Treatment Systems, Water Authority — Cesspool Emptier's Licence, Water Authority Act (2022 Revision), Water Authority Regulations (2022 Revision), Water Authority — Additional FAQs, Water Authority — Best Management Practices, Department of Planning — Plumbing Plan Review Guidelines.