EWB-DC Events Calendar

Please join us to continue the discussion of storage tank design for the water system in Shiringamazu. 

We are looking for designs for circular tanks that we can use as a starting point to then finalize into a site-appropriate design drawing that can be sent to the contractor for cost estimates. 
We are also looking for insights about water-proofing methods during construction of cylindrical tanks.

There are two sets of rectangular Concrete Tanks drawings we have gathered as a starting point for our design. Bring your ideas about adopting one of these drawings for our purposes, waterproofing measures we should include, and/or changes we might need to make.

Also, please bring your professional opinions about waterproofing options for circular vs. rectangular concrete tanks. 

We will continue the river crossing topic in the following meeting. Here is a document investigating local materials options for the hangers. https://docs.google.com/document/d/1VKCwl4viWt4oqNU1s0zXCZ1LNXEbqFo3-nPuLkzF664/edit?usp=sharing

Below is a summary of the last meeting.

26 March Meeting Minutes Summary:

The meeting reviewed final design decisions for the river crossing, and touched on the design for water storage. The host identified river crossing, storage, and tap stands as the primary open items to resolve before the trip.

Participants examined recently received field data and photos for two candidate trees for a cable-supported pipe span and noted highest recorded water levels that could reach about 1 m on one trunk and 2 m on the other, raising clearance and sag concerns and suggesting attachments must be placed high enough to account for sag and ability to cinch the cable with sufficient tension. Don Lieu provided  preliminary pipe weight and hanger-spacing numbers (water weight ~4.2 lb/ft, hangers every 5–6 ft, roughly 20 hangers), and proposed scaffolding/pipe-hanger details. He requested structural-engineering input on cable-to-tree attachments and load capacity. The team agreed the in-country photos do not show sufficient detail to confirm attachment methods and that hanger selection must consider locally available materials.

The group evaluated tree measurements, species, and attachment locations and judged the trees substantial enough for a cable-supported span while noting branching limits for attachment points. Attachment methods were debated—through-bolts versus wrap/strap—and alternatives such as a mid‑river pier were discussed, with a preference to avoid new civil work. The team agreed on two concrete next steps: run catenary and sag calculations to size elevation and hanger spacing, and evaluate tree-attachment methods using reference material in the shared drive. Structural-serviceability concerns (sag, wind, vibration, and rain loads) and a safety-factor discussion noted that sag/deflection will likely govern required tension. Participants raised hanger-material corrosion concerns and the need for hangers wide enough to avoid cutting into HDPE, and assigned tasks for preliminary calculations and local sourcing research. Angeline Cione confirmed that the contractor was interested in constructing a circular tank and requested the group seek existing drawing for cylindrical ferro-concrete tanks. Once finalized, the design will be sent to the contractor for a cost estimate.

Please join us to continue the discussion of the river crossing for the water system in Shiringamazu. 

We will review a draft design based on our last meeting and calculations run by Dipesh, Jhon, and Vedant.

We will also review the two common methods used for hangars in Peru and locally available materials. 

Here is a document investigating local materials options for the hangers. https://docs.google.com/document/d/1VKCwl4viWt4oqNU1s0zXCZ1LNXEbqFo3-nPuLkzF664/edit?usp=sharing

Here is the stream crossing folder on the drive: https://drive.google.com/drive/folders/1ny9qiaCsP0p2o9l0TzhMmFHYdayGnGcS?usp=drive_link

Below is a summary of the last meeting, 2 April Meeting Minutes Summary:

The meeting evaluated storage designs for a mountain route site. The team reviewed the approved reservoir scheme of three 5,000‑liter plastic tanks (15,000 L total) and reiterated concerns about the limited footprint at the identified roadside sites, then compared alternatives that could increase capacity within the same footprint, including a single concrete or cylindrical ferrocement tank that could provide at least 20,000 liters and is preferred by local municipal maintenance for lower upkeep. Christopher referenced past 20,000‑L work and Kansas City chapter designs in EWB files, and agreed to pursue those references.

Discussion then focused on two contiguous candidate footprints (an old‑site ~3.0 m × 12 m and a new‑site ~3.8 m × 10 m) and modest minimum envelopes near a recurring ~3 m clear diameter, constructability constraints, and structural needs (footings, concrete thickness, reinforcement, seismic restraint). The videos of the sites are here: Concrete Tanks The team compared circular versus shallow rectangular geometries, noted circular tanks give better volume efficiency and use less concrete, reviewed freeboard and thickness conventions, and flagged steep drop‑offs, red clay soils, and landslide risk that require erosion‑control and minimized excavation. Angeline noted a concern about waterproofing that could be addressed with admixes in the concrete. Action items were assigned to share drawings and videos, produce a volume comparison spreadsheet, and circulate design examples before the next meeting.

Cylindrical tank folder: https://drive.google.com/drive/folders/1eiLvxxdP80mNtIAMvrKTt5q4FSjriQmf?usp=drive_link

In addition to our Thursday design meeting for the river crossing, we will be meeting on Friday to review the spring capture design and the break pressure tank design. We will specifically be discussing options for O&M cleaning of the water system as well as general review and discussion of the design.
Everyone is invited, especially those with spring capture construction experience. Anyone planning to travel the first and second weeks of our trip (June 27-July4) and (July 4-12) should attend this meeting because we will be implementing these components during those weeks.

Please review the designs at the links below:

Spring Catchment:  https://drive.google.com/drive/folders/1xM645OL_YmzP6ensNYjAeVUxvrYQZde5

BPT: https://drive.google.com/drive/folders/1cp5eAHgwL0cNeUYjofJYgGK4_YA6riTB

Please join us to continue the discussion of the river crossing and water storage tanks for the water system in Shiringamazu. 

We will review draft designs and start materials lists.

Cylindrical tank folder: https://drive.google.com/drive/folders/1eiLvxxdP80mNtIAMvrKTt5q4FSjriQmf?usp=drive_link

Here is a document investigating local materials options for the hangers. https://docs.google.com/document/d/1VKCwl4viWt4oqNU1s0zXCZ1LNXEbqFo3-nPuLkzF664/edit?usp=sharing

Here is the stream crossing folder on the drive: https://drive.google.com/drive/folders/1ny9qiaCsP0p2o9l0TzhMmFHYdayGnGcS?usp=drive_link

Below is a summary of the last meeting, 9 April Meeting Minutes Summary:

The meeting convened to advance a design for a water pipeline that will be suspended between two trees across a creek, and to resolve installation sequencing and hardware choices. The group confirmed the pipeline alignment (not the walking survey path), agreed GPS centerline confirmation would be provided, and reviewed tree-preservation constraints that led them to favor a single cable routed through hardware rather than opposing choke forces on trunks. Participants discussed whether diagonal cables should be load-bearing anchors or lightly tensioned guides and weighed redundancy against ease of tensioning and repair.

The team examined mechanical details for the span, including hanger geometry, spacing, pipe attachment options (wire loops, threaded rods, and flat-bar cradles), and tensioning methods. Dipesh presented calculations that set attachment height near eight feet, hanger drop of about one foot, and target mid-span deflection of roughly two feet empty and three feet filled, with a maximum anticipated deflection of about five feet when full. The group preferred assembling the cable, hangers, and empty pipe on the ground before raising and tensioning, and agreed to verify local availability of tensioning tools in Peru. For installation, they favored using a chain hoist to raise and hold the system during adjustments, then transferring load to a turnbuckle, and discussed temporary supports such as scaffolding and tree-saver straps to protect trees and improve safety while working at height.