Lake Ontario is a hotbed for dimensional weirdness. Parareligions have historically exploited it to aid in their magics, things like the eels slip out of extradimensional space routinely, and if you've ever worked with the Nu-3 crew, chances are you've seen pockets of the lakebed that are larger than the lake itself. The reality researchers argue about what phenomena are at work and Multi-U tries to use this as best as they can for multiversal travel. That's all beyond us.
Point is that, since 1999, we've been trying to lock down on the weird. The Department of Occult Containment constructed the Arete Dimensional Array running across the lakebed, intended to monitor every blip in spacetime and seal up anywhere deemed too dangerous. More mazes of pipes and sensors than most containment sites have. Does it stop dimensional weirdness entirely? No — you can't contain an entire lake. Does it make our lives a lot easier? Yes.
Of course, this runs into problems. Sometimes wormholes will open in the middle of equipment or near it, and as that repeats precipitate builds up. Junk from alt universes, creatures that barely qualify as animal life…
Here, look this over. I think it should be more useful than me blabbering on.

Incident Date: 07/08/2004
Overview: Maintenance Crew Lamedh discovered the cadaver of a tripedal entity, fused with the primary access hatch to the E/1 Pipeline. Upon clearing the cadaver, Crew Lamedh entered the pipeline and found an ecosystem of fauna and flora inhabiting its interior. All organisms bore resemblance to the tripedal entity, and are suspected to have relied on the electricity transported through the pipeline's cable bundles as an energy source. The colony died after 10 minutes without an electricity supply.

Site-201 Containment: Arete Dimensional Array

Recovered Precipitate Matter: 2006—2010

Fragments of the Alexander Mosaic, its construction matching that of the ancient Roman mural in baseline reality. The sole difference is the presence of M4 Sherman tanks in the place of each individual's head.

A cathedral built in the Gothic architectural style. Statues of human bodies fused into a spherical mass and adorned in crowns lined the walls, and stained glass windows depicted a planet entirely surrounded in Gothic structures. The cathedral, having been constructed from cardboard, dissolved over the course of two hours.

[…]

Incident Date: 19/09/2006
Overview: 100m3 of sapient gelatinous material blocked the Point B maintenance tunnel. The mass vocalized to maintenance crews in French, repeating that it had "transcended to the highest universe." Vocalizations continued as the gel was drained.

Incident Date: 03/02/2007
Overview: Maintenance Crew Dalet had their submersible followed by a remotely operated underwater vehicle (ROV), which stayed at a constant distance of 20m from the vessel. The Foundation seal was emblazoned on its side. Activity lasted for two hours until it vanished.

[…]

A truck holding 50 copies of Oh the Places You'll Never Go!, an illustrated book in a similar style to Theodor Seuss Geisel that depicts anomalous locales and city states. The author is listed as "Dr. Blackwood." Water damaging has prevented thorough analysis.

The solidified concept of "inhaling." The material was visualized as a crystalline structure composed of disembodied human mouths, and it would absorb all gasses or dispersed particles that contacted it. Maintenance crews found it blocking the D/1 Elan-Vital Energy funnel, absorbing the funnel's thaumic energy supply. Neutralization was completed by breathing on the substance.1

Eight surveillance devices found in various areas of the Arete Dimensional Array. Each is equipped with underwater thrusters, claws to grip to surfaces, and camera equipment. Notable similarities to the construction of the ROV encountered on 03/02/2007 exist.

[…]

Incident Date: 05/10/2008
Overview: The body of 100m long blue whale (Balaenoptera musculus) clogged the D/1 funnel. A flag depicting a whale extended from the blowhole, and the cranium was found to contain a "command center" where dead, 3m long blue whales were positioned at computer terminals. The craniums of these whales contained further command centers with smaller whales.

Incident Date: 24/06/2009
Overview: A wormhole opened at the Point E lakebed station, producing an organism identical in size and shape to Point E and its connected pipelines. The organism initiated in behaviors believed to be part of a courtship display but accidentally self-neutralized when a pipeline "tendril" collided with a Scranton Reality Anchor. Full information on the ensuing reality destabilization is restricted.

Incident Date: 11/03/2010
Overview: Sensors detected a burst of thaumic particles near the Point A lakebed station. Readings corresponded to the artificial opening of a Way leading from an extradimensional space. Mobile Task Force Nu-3 ("Limnophobia") was scrambled to the area but found no signs of residual thaumic energy, Way activation, or any form of dimensional instability deviant to the local baseline.
No signs of malfunction were present in the sensors. Monitoring of the area was increased.

[…]

A sealed metal container marked with "WARNING: FOOD WASTE INSIDE. DISPOSE AT ONCE." All container contents were Allison Eckhart-Class Allison Eckhart Hazards and had to be jettisoned into dimension AE-9870 to prevent Allison Eckhart dispersal through Lake Ontario.2

[…]

Incident Date: 11/04/2010
Overview: The full staff of Maintenance Crew Aleph, working on Point A exterior plating, reported a sense of being watched to Command. No observations with sonar, infrared, or other such viewing equipment found signs of abnormalities. Work proceeded as planned.

Incident Date: 11/05/2010
Overview: Maintenance Crew Aleph claimed to have found an excess of "nothing" encompassing the Point A Power Generator. Crew Aleph used all available tools to try and remove the excess, in one case using underwater mines to destroy the "nothing," damaging the generator in the process. Out of concerns regarding memetic infection, MTF Nu-3 was dispatched to investigate.
MTF Nu-3 reported that nothing was present.

[…]

A large mechanical entity emblazoned with the Foundation seal, equipped with four humanoid containment units, eight tendrils, and homing torpedoes. The entity had projected a metaphysical cloaking barrier while at the Point A Power Generator, disabling it to attack Maintenance Crew Aleph on 11/06/2010. Four personnel were pulled into its containment units before it attempted to conjure a Way. The threat was neutralized when Agent A. Bridger rammed its "head" into a nearby dimensional tear with a submarine, severing it.3

END OF REPORT

Documentation supplied by the Site-201 Dimensional Oversight Committee.
Further information may be provided on request.
SECURE, CONTAIN, PROTECT.

Bear in mind that this is the craziest of what we get. Most of the time it's more mundane, like four-sided triangles and creatures bending along seven spatial axes, but when it escalates it escalates hard.
With that said, welcome to Aleph Crew of Zeta-0, Plumbing Duty. This is how the job will go: when Command sends the signal we'll suit up, hop in the nearest submersible, and dive off to anywhere maintenance is needed. Doesn't matter how broken or how dangerous it is. We will get there and we will fix it. You'll be the one keeping all our paratech in check. If our auto-exorcists can't excise another reality's demon, that's on you. Don't screw it up.
Oh, and before I forget, don't swim near any dimensional tears. It's easier to fall out of reality than you'd think.

Footnotes
1. Conceptual fragments in the vicinity corresponded to "sinking," "flailing," and "drowning."
2. How such a large quantity of Allison Eckharts could be stored in the container without suffocation occurring is unclear.
3. No contacted multiversal Foundations have claimed responsibility for this and the previous surveillance incidents.