16.1 Seasonal Shutdown and Opening Turnover

16.1 Seasonal Shutdown and Opening Turnover

Quick Answer: Closing a public pool is a documented maintenance turnover, not a locked gate and a hope. Finish with a last shock so the basin does not sit green, then decide with the authority having jurisdiction (AHJ) and climate whether to lower water or keep it up under a cover. Blow or drain exposed lines, protect skimmers with freeze plugs or ice-compensating devices (often called gizzmos), and use antifreeze only where the manufacturer and AHJ allow—never dump toxic glycol into a public pool. Cover, secure, disable feeders, lock out gas chlorine, and photograph the condition. Opening is the reverse critical path: inspect the basin and Virginia Graeme Baker (VGB) covers, fill, start circulation, clean the filter, balance water, heat, restore safety equipment and the ADA lift, confirm the health permit, and write logs from day one. In a warm climate, shutdown is often a short repair outage, not a freeze-out.

Chapter 12 taught weatherizing: how you keep a still-open facility alive through lightning, rain, heat, and a shoulder-season freeze watch. This section is the other half of facility maintenance topic 5C: mothballing a basin that will sit, then bringing it back as a legal public pool. Chapter 13 pointed feature winterization here. Chapter 14 owns the preventive-maintenance calendar you run before you hang the closed sign. Chapter 15 owns the file where opening and closing reports live. Independent OpenExamPrep teaching uses ordinary commercial winterization practice, U.S. Consumer Product Safety Commission drain-cover rules, OSHA energy and chemical isolation, and AHJ pre-opening inspections. OpenExamPrep is not an NRPA shutdown crew and does not publish a national freeze date.

Closing is a climate decision, not a calendar superstition

A Minneapolis outdoor pool in September and a Miami outdoor pool in September are not the same job. The northern plant faces ice expansion, burst piping, and months of unattended water. The southern plant may close for budget, staffing, or a plaster contract and never see ice. Treat both as shutdowns. Do not copy a freeze-out checklist onto a ten-day tile repair, and do not skip isolation on a warm-climate close because it never freezes here.

Indoor natatoriums add a third pattern: a holiday or renovation outage in a heated building. There may be no ice in the yard, but there is still a drained feature, a contractor in the tank, and a chlorinator that will bleach an empty loop if you leave it in automatic. The shared rule: name the outage type on the closing report so the next shift does not apply Minnesota hardware to a Florida plaster job, or skip lockout because the building is warm.

Last chemistry, then stop feeding

Stagnant water grows algae and a biofilm that opening staff will spend a week scraping. Before you disable the plant:

1. Brush walls, floor, and tile line. Algae you leave is algae you reopen with.
2. Clean the filter so you are not storing dirty media for six months.
3. Bring free chlorine up with a last shock appropriate to the product you use (Chapter 4 owns breakpoint math). The goal is oxidation and a residual that lasts into the idle period—not a number invented as the NRPA close-out ppm. This guide will not invent unpublished official residuals.
4. Balance pH and total alkalinity so you do not sit all winter in etching or scaling water (Chapter 5). Plaster and heaters remember off-season calcium saturation index (CSI) abuse.
5. Then disable feeders. An erosion feeder dripping into a lowered basin, or a peristaltic pump running into a dead loop, is how you bleach a liner or dump acid into an empty line.

If you operate gas chlorine, treat shutdown as a lockout: valves closed, cylinders secured or returned per your process, feed system isolated, authorized staff only. A drained pool with a live gas chlorinator is a release waiting for a confused contractor. Chapter 11 already taught that gas work is trained and authorized only. This section adds do not leave it enabled on a mothballed plant.

Write the last chemistry line, the feeder-off time, and who isolated gas when it happens. Chapter 15 already banned backfilling. Closing week is where backfilling is most tempting because the park is empty.

Lower the water, or do not

Ice that forms in a full skimmer or in an exposed return can crack the fitting. Ice that forms in a drained basin with a high water table can float the shell if hydrostatic relief is ignored. Those two sentences are why always dump it and always leave it full are both wrong.

Decide with climate, cover type, manufacturer, and AHJ:

• Lower below skimmer and tile in freeze climates when that is the local method: ice forms on a lowered surface, skimmers get plugs or ice-compensating devices, and you are not asking a full vessel to freeze in the throat of every fitting.
• Keep water up under a fitted cover when the AHJ and the cover design expect a full pool. That pattern is common with some safety or winter-mesh systems, and with many indoor basins that are only down for a repair.
• Do not drain plaster in a high-groundwater season without hydrostatic plugs or relief and someone who understands that a hollow concrete boat will try to float.
• Some health codes restrict draining to waste or to stormwater. We always dump to the parking lot is not a discharge permit.

Spas and therapy tanks follow the same logic at a smaller volume: air loops, blower lines, and skimmer throats freeze faster than a 12-foot municipal well. Features from Chapter 13—slides, spray pads, dump buckets—are not optional footnotes. If the pad laterals hold water, they are freeze pipes with nozzles on the end.

Document the water-level decision and valve positions in the closing report. Opening staff should not have to guess whether the puddle in April is intentional or a leak.

Blow, drain, plugs, and the antifreeze rule

Exposed piping, water-feature loops, slide runouts, spray-pad laterals, outdoor showers, and chemical-feed lines that sit in unheated space must not hold a column of water that will freeze and split the pipe. Common methods:

• Drain the line to a low-point or fixture.
• Blow with air from a compressor the piping is rated for. Too much pressure cracks fittings as surely as ice does. Follow the manufacturer; this guide will not invent a national psi table. Keep unauthorized staff off the air hose.
• Skimmer freeze plugs block the equalizer or throat so ice is not pumping into the line.
• Ice-compensating devices (sold under names such as gizmo) thread into the skimmer so expanding ice pushes a collapsible or sacrificial piece rather than the throat. Teach the concept: give ice a place to go. Do not treat a brand name as an NRPA statute.

Antifreeze is the most misused close-out chemical.

Public-pool operators meet two household names that do not belong in the basin:

• Automotive ethylene glycol is toxic engine antifreeze. Never dump it into a public pool, spa, gutter, or deck drain that can reach bathers, pets, or wildlife.
• RV or plumbing antifreeze is often propylene glycol and may be labeled for potable lines. It is still a chemical, not pool water. Use it only in isolated piping if the manufacturer and AHJ allow. Do not dump leftover RV antifreeze into the pool and call that winterization.

If a line cannot be drained or blown, get a method the equipment maker and AHJ will stand behind—heat tape, burying, or a listed plumbing antifreeze confined to that line—and document it. Opening turnover includes flushing any allowed antifreeze to a legal waste, not into the deep end. Do not recommend pouring glycol of either flavor into a public pool to keep it from freezing. That is how you contaminate a water body you will have to drain, neutralize, and explain to the health department.

Feature close-out from the Chapter 13 handoff: blow spray-pad laterals, drain dump buckets, isolate slide pumps, and do not store acid in a feature day tank over the winter as a freeze strategy.

Cover, security, and photographs

A winter cover keeps leaves, animals, and people out of a lowered basin. A cover is not automatically a legal barrier; follow the AHJ and the cover listing. Fasten it so wind does not turn it into a sail. Pump standing water off a solid cover so it does not become a second drowning hazard.

Security is part of shutdown: gates latched, chemical rooms locked, keys accounted, lighting that still works for police drive-bys, and feeders off. A closed park is still an attractive nuisance. Disable automatic fill if a stuck valve will flood a lowered winter pool—or leave a plaster job underwater overnight.

Documented photographs at closing are not decoration. Shoot the basin finish, waterline tile, drain covers (seated, with enough context to identify the fitting), cover installation, mechanical-room isolation, and any damage you are handing to a contractor. Timestamp them into the Chapter 15 file. Opening disputes—that crack was already there—are won or lost on closing photos.

Warm-climate and indoor shutdown: a repair outage, not a freeze-out

A ten-day plaster contract in Tampa, a filter-grid replacement in Phoenix, or an indoor natatorium closed for a university break is still a shutdown:

• Post the close, notify the AHJ if required, and keep security.
• Isolate the work zone so plaster dust or a contractor hose does not become your sanitation plan.
• Disable feeders into an empty or drained section. Do not keep chlorine legal in a basin with no water.
• Lock out pumps and gas as OSHA energy control requires before anyone opens a strainer or a heater (Chapter 8).
• Skip gizzmos and antifreeze unless a genuine freeze is in the forecast.
• Keep a short punch list for the day you refill: covers, circulation, clarity, residual, lift, permit.

Confusing this outage with Minnesota winterization wastes labor and can put glycol where it does not belong. Confusing it with just lock the gate leaves a live chlorinator and an open chemical room.

Worked contrast: same agency, two sites. Site A is a seasonal outdoor 75 ft by 25 ft basin in a freeze climate. Closing week includes last shock, lower below skimmers, blow exposed returns, install ice-compensating devices, winter cover, gas lockout, photos. Site B is a Gulf Coast outdoor pool closed 12 days for tile. Closing is isolate the tank, lock out the pump, disable feeders, fence the work, photograph the existing finish, and leave the freeze kit on the shelf. Both are 5C shutdowns. Only Site A is a freeze-out.

Opening turnover: inspect, fill, circulate, then invite the public

Opening is not turn on the pump and unlock the turnstile. The critical path is inspection first, chemistry second, people last.

1. Inspect the basin. Walk the floor, or use a clear-water look as you fill. Look for cracks, missing tiles, sharp joints, leftover antifreeze odor, animals, and debris. Chapter 15 owns finish repairs. This section owns do not fill over a hazard you have not named.
2. Inspect suction outlets (VGB). Spell Graeme. Confirm covers are the listed make and model, seated, hardware tight, and within the manufacturer or AHJ replacement date (Chapter 11). A winter ice event can pop a cover. A cover that looks fine but expired in February is still a close.
3. Fill with water you have tested at the tap. Chapter 12 makeup-water chemistry still applies at opening. Watch hydrostatic behavior if the basin was empty.
4. Start circulation with valves in the open, legal configuration. Prime the pump as Chapter 7 taught. Do not run a heater or a feeder on a dry loop.
5. Clean the filter (backwash sand or DE, clean or replace cartridges). Winter silt and opening debris load media fast.
6. Balance water and restore a legal free-chlorine residual. Expect a first-week demand spike from biofilm and dust. Combined chlorine at opening is a Chapter 4 problem, not a reason to skip filtration.
7. Heat only after flow is proven (Chapter 7 interlock). Scaling water from a neglected off-season CSI will crust the exchanger on week one.
8. Safety equipment back on the deck: reaching poles, buoys, first-aid, emergency action plan posted, emergency phone, depth marks visible, spa clock if you have a spa.
9. ADA lift in service: charged, in its location, working the first public day—not when the battery comes in next Thursday (Chapter 10). If the lift was stored dry for winter, reinstall it before the inspector, not after the first complaint.
10. Health permit / pre-opening inspection as the AHJ requires. Many seasonal pools may not legally admit bathers until the inspector has signed. Schedule that visit before the advertised first Saturday.
11. Logs from day one. Even a staff-only fill day gets chemistry, who opened, and what failed. Backfilling opening week after the first Saturday is the Chapter 15 falsification problem.

Worked opening trap: closing photos in September showed a seated drain cover with a manufacturer expiration the following March. If opening staff skip the VGB file, they may fill, heat, and staff a pool whose cover expired during the off-season. The correct opening move is replace the cover before the public hour, not we will order it after the first weekend.

Close versus open critical path

That table is operator sequencing, not an NRPA statute and not a substitute for the manufacturer's winterization sheet. If the maker's instructions and the AHJ disagree, the inspector's code still wins on legality; the maker still wins on what will crack the pipe.