Constructing a modular water biofiltration system to handle the scale of water usage required for shower water recycling involves multiple filtration and sterilization stages, all housed in IBC tanks for modularity and scalability. Here’s a step-by-step breakdown: ![[Pasted image 20241017224246.png]] ### System Overview The system will consist of several stages: 1. **Accumulate and Pre-filtering Stage**: Collects and screens large debris. 2. **Biofiltration Stages**: Employs living systems to remove organics and contaminants. 3. **Slow Sand/Charcoal Filtration**: Filters fine particles and absorbs remaining impurities. 4. **UV Sterilization and Filtration**: Kills harmful microorganisms. 5. **Hybrid Solar/Electric Water Heater Tank**: Stores clean water at elevated temperatures. 6. **Pumping System**: Circulates water through the filtration stages and back to showers. ### Stage-by-Stage Breakdown #### 1. **Accumulate and Pre-filtering Stage** - **Number of IBCs**: 1 - **Setup**: Water from showers drains into this IBC where large debris (hair, soap scum) is removed through a pre-filter (mesh or filter cloth). - **Pumping**: A submersible pump moves the pre-filtered water to the next stage. #### 2. **Biofiltration Stages** - **Number of IBCs**: 2-3 (depending on the system's complexity) - **Setup**: Water is distributed through a series of IBC tanks that house biofilters, which could consist of various types of media (gravel, plant roots, microbial biofilms) that naturally break down organic materials. - **First Tank**: Gravel bed filter supporting plants or bacteria (reed bed style). - **Second Tank**: Additional bio-media like activated sludge or trickling filter media. - **Third Tank**: Optional, another stage of biological treatment or secondary settling. - **Pumping**: The water is pumped sequentially from one biofilter IBC to the next. #### 3. **Slow Sand/Charcoal Filtration** - **Number of IBCs**: 2 (1 for slow sand, 1 for activated charcoal) - **Setup**: The slow sand filter removes fine particulates while the charcoal filter adsorbs organic chemicals and odors. The filters work best under low-flow conditions to allow for deep filtration. - **Pumping**: After passing through the biofilters, water is pumped into these tanks for additional filtration. #### 4. **UV Sterilization and Filtration Stage** - **Number of IBCs**: 0 (UV does not require an IBC but is installed inline). - **Setup**: After the slow sand and charcoal stages, the water passes through a UV sterilizer that eliminates bacteria, viruses, and parasites. UV units are placed inline between the charcoal filter and the water heater. #### 5. **Hybrid Solar/Electric Insulated Water Heater Tank** - **Number of IBCs**: 1 (insulated to serve as a water heater) - **Setup**: The treated water is stored in a modified insulated IBC tank that acts as a water heater. This tank is equipped with solar water heating tubes (or coils) on the outside and a backup electric heater. The thermostat controls ensure the water is maintained at safe temperatures for hygiene. - **Thermostatic Mixing Valve**: Regulates the temperature to prevent scalding and ensure proper mixing of hot and cold water. - **Pumping**: The pump system circulates heated water to the showers when needed. ### Total IBC Modules and Layout The entire system requires **6 to 7 IBC tanks** in total: - 1 for accumulation and pre-filtering. - 2-3 for biofiltration stages. - 2 for slow sand and charcoal filtration. - 1 insulated IBC for the water heater.  The IBC tanks are connected sequentially using PVC piping or flexible tubing. Each tank will have an inlet and outlet, and the tanks will be elevated slightly so gravity helps to drain water into each successive tank, reducing the need for pumping power. ### Pumping System - **Submersible Pumps**: At least two pumps are recommended. One will move water from the accumulation tank through the biofilters, and the second will push the water from the final stage (UV and heating tank) back to the showers. - **Solar-powered or Electric**: The pumps can be powered by solar panels, reducing reliance on the grid. A battery backup system ensures pumps continue running when sunlight is insufficient. ### Catchment and Water Replenishment Since the system operates semi-open, water from rain (collected by the catchment system) is filtered and added to the IBC system periodically to replenish the clean water supply. Excess water from the showers can also be reused. --- By employing this modular system with IBC tanks, the community can scale the filtration to meet specific water demands while keeping costs low, utilizing globally available materials. The result is a decentralized, modular water filtration and heating system that is resilient, adaptable, and energy-efficient. For a modular water biofiltration system suited for the scale of the shower water system you're considering, wetland plants and riparian species play a key role in filtering out contaminants. Here’s an outline of how to construct the biofiltration system, with specific wetland plants from the Salton Sea area. ### Key Design Considerations: 1. **Modular Structure:** Each biofiltration module is based on an IBC tote with an open top for plant growth. The charcoal/sand/gravel filters are layered at the bottom, while the biofiltration occurs at the surface as water percolates through the plant roots and then flows down through the filter media. 2. **Flow Design:** Water is directed into the bottom of each biofiltration module from the overflow of the previous one, moving through layers of filter media and percolating upwards as it moves into the next module. 3. **Stages:** - **Pre-filtering Stage:** Large particulates are removed through coarse filters or settling tanks before water enters the biofilters. - **Biofiltration Stage:** Open-top IBC tanks filled with a mix of aquatic plants and filter media, each module acting as an independent stage for different biological processes. - **Slow Sand/Charcoal Filtration Stage:** Layers of sand, gravel, and biochar at the bottom of each module further filter the water. - **UV Sterilization:** After the final biofiltration stage, UV sterilization ensures pathogen elimination before water is stored or heated. - **Water Heating:** A hybrid solar/electric insulated water heater with a thermostatic mixing valve stores the water at elevated temperatures, which can then be mixed to safe shower temperatures. ### Suggested Native Plant Species for Biofiltration: 1. **Cattails (Typha domingensis)** – These grow naturally in the wetlands around the Salton Sea. Their roots help absorb nutrients and filter out heavy metals and organic compounds. 2. **Common Reed (Phragmites australis)** – Another species common to the area, it’s excellent at uptaking nutrients, reducing nitrates and phosphates in the water. 3. **Sedges (Schoenoplectus acutus)** – Known for their ability to thrive in wet conditions and filter water effectively. 4. **Yerba Mansa (Anemopsis californica)** – A riparian species that helps in phytoremediation by absorbing contaminants from the water. 5. **Saltgrass (Distichlis spicata)** – A salt-tolerant species that could be used in brackish water filtration modules. 6. **Algae, Duckweed, and Azolla (optional stages)**: - **Algae Cultivation:** Helps absorb excess nutrients, such as nitrogen and phosphorus, and can be harvested for biofuel production. - **Duckweed (Lemna minor)**: Fast-growing and nutrient-rich, duckweed can help purify water and be harvested for animal feed or compost. - **Azolla:** This small, floating fern grows rapidly and can fix nitrogen, further cleaning the water and adding biomass that can be harvested. ### Filter Media: Each biofiltration module will have a layering system: - **Top Layer (root zone):** Reedbed plants like cattails and reeds absorb nutrients from the water. - **Middle Layer:** Biochar (charcoal) mixed with sand to trap particulates, metals, and pathogens. - **Bottom Layer:** Coarse gravel to promote drainage and allow water to percolate upwards for filtration. ### System Layout and Pumping: 1. **Number of IBC Modules:** For a community of 30 people with significant shower water usage, around 4 to 6 IBC modules would likely be necessary for biofiltration. One or two of these could be devoted to algae and floating plant cultivation. 2. **Pumping System:** A low-energy pump, possibly solar-powered, would direct water from one module to the next in sequence, ensuring the correct flow rate for each stage. 3. **Overflow Management:** The overflow from each module is directed to the bottom of the next module, promoting vertical filtration from the roots of the plants down through the filter media. ### Water Heating: After the water passes through the biofiltration system, it would be heated in an insulated solar/electric water heater tank. A thermostatic mixing valve ensures water is stored at high enough temperatures to prevent microbial growth, then mixed to deliver safe temperatures for showers. ### Rainwater Harvesting Integration: The system could also be connected to a rainwater catchment system, where water is collected and stored for shower use, reducing dependence on external water sources and improving resilience. This system provides a low-tech, nature-based solution that leverages local biodiversity and modular design for efficient water filtration. To focus solely on the shower water needs without including drinking water, let's revise the calculations: ### Shower Water Demand For a community of 30 people, each taking two showers per week with each shower requiring 10 gallons of water, the total shower water demand over 3 months is: \[ 30 \, \text{people} \times 2 \, \text{showers/week} \times 12 \, \text{weeks} \times 10 \, \text{gallons} = 7,200 \, \text{gallons} \] This is equivalent to **27,255 liters** of water over 3 months. ### Evaporation and Water Recycling Efficiency In the climate of Bombay Beach, CA from January to April, there would be some loss due to evaporation. Assuming the system is designed for high-efficiency water recycling, let’s assume: - **80% recycling efficiency** (water that is recycled and reused), - **20% loss** to evaporation (due to dry, arid conditions). ### Evaporation Loss Calculation Over 3 months, the **20% evaporation loss** would mean: \[ 20\% \times 7,200 \, \text{gallons} = 1,440 \, \text{gallons} \] This is equivalent to **5,451 liters** lost to evaporation over 3 months. ### Recycled Water The remaining **80% of the water** will be recycled and reused for showers: \[ 80\% \times 7,200 \, \text{gallons} = 5,760 \, \text{gallons} \] This is equivalent to **21,804 liters** of water that will be recycled over 3 months. ### Initial System Fill and Total Water Needed Since 20% of the water will be lost, the community will need to replenish about **1,440 gallons** (5,451 liters) over the 3-month period. - **Initial fill:** The system will need enough water to start with. A total of **7,200 gallons (27,255 liters)** will be required for the entire 3-month period, but because of recycling, you only need to replace the lost 1,440 gallons over time. ### IBC Tanks Required Each IBC tank has a capacity of about **1,000 liters** (264 gallons). - For **27,255 liters (7,200 gallons)**, the initial system fill would require about **28 IBC tanks** worth of water if there were no recycling. - However, with recycling, you’ll only need to store **about 6 IBCs worth** of water to circulate through the filtration system, plus some buffer for losses due to evaporation. **Conclusion:** You won’t need additional IBCs just for storing the cleaned water. The total amount of water to be managed for shower use can be comfortably stored and filtered through **6-8 IBC tanks** in the system, with the **6 IBCs** handling the bulk of the recycling and storage, and perhaps **1 or 2 additional tanks** acting as buffer storage to replace evaporated water over the 3-month period. ### Rainwater Catchment If we assume **0.8 inches** of rainfall over the 3 months and need to collect **1,440 gallons** to offset evaporation: 1. **Catchment area calculation:** - 0.8 inches of rain is about **0.0667 feet**. - For 1 square foot of catchment, **0.0667 feet of rain** provides **0.0667 cubic feet** of water. - There are **7.48 gallons** in a cubic foot of water. So, each square foot of catchment area provides: \[ 0.0667 \, \text{feet} \times 7.48 \, \text{gallons/ft}^3 = 0.5 \, \text{gallons/ft}^2 \] To collect **1,440 gallons** of water: \[ \frac{1,440 \, \text{gallons}}{0.5 \, \text{gallons/ft}^2} = 2,880 \, \text{ft}^2 \] The community would need a **2,880 square-foot catchment area** to collect enough water to meet their 1,440-gallon shower water requirement over 3 months, assuming no additional water losses.