## 2 Materials and Methods
### MFCS Energy Impact Calculation Method  
The energy demand per day (kWh) for the WFs is the results of Equation (5) in [51], the energy demand (kWh) per day for the LI is the result of Equations (6)-(9) (ibid.). The power (kW) and energy (kWh) demand for LI was developed from Equations (6)-(9) as adapted from [PERSON] and [PERSON] [60] in [PERSON] et al. [51], which were specifically developed for crop irrigation. In addition, the power (kW) and energy (kWh) demand for the WFs were developed from the swimming pool calculation methods [61; 62] as per Equation (5) in [PERSON] et al. [51], with the addition of the pumps' frequency of use. It is estimated that the transfer pumps are used 30% of the time, and the backwash pumps 10% of the time.  
These calculation methods are like the basic theoretical pump power and pump energy intensity calculation methods of [PERSON] [63], [PERSON] [64], and [PERSON] et al. [65]. However, these, like the MFCS calculations, do not include factors for pump power standby-mode and pump power start-up [66; 67] due to the lack of information on the number of start-up operations per pump and the power rate for standby mode (see Table 4 for the different calculation methods analyzed by the author). According to [PERSON] et al. [67] and [PERSON] et al. [68], 60% to 69% more energy is used when considering pump standby-mode and pump power start-up in the equation. However, these authors did not consider the shutdown mode for system maintenance, which may also influence the results. Thus, according to the Table 4 literature review [51], the proposed MFCS calculation is a simple method.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{2}{c}{**Literature Review**} & \multicolumn{2}{c}{**Method for Calculating Pump Energy Intensity**} & \multicolumn{1}{c}{**Water End-Use**} \\ \hline \hline  & & Pump Input Power (kW) & Rainwater reuse for \\  & & Pump Flow rate in cubic meter per hour (m\({}^{3}\)/h) & toilet flushing and \\  & [67] & Pump Start-up (kWh/start-up) & & laundry supply in \\  & [66] & Number of start-up operations (start-up/day) & & single-story \\  & & Power rate of standby mode (kW) & & detached house \\  & & Standby mode (hours/day) & & detached house \\  & & Rainwater consumption (m\({}^{3}\)) & & \\ \hline \hline  & & Volume pumped during constant flow operation (m\({}^{3}\)) & \\  & & Volume pumped during start-up (m\({}^{3}\)) & & \\  & & Start-up energy factor (\%) & & Rainwater reuse for \\  & & Motor pump power rating (kW) for efficiency calculation & toilet flushing in \\  & & Motor input power (kW) for efficiency calculation & office building \\  & & Pump capacity (m\({}^{3}\)/h) & & \\ \hline \hline  & & Liquid density in kilogram per cubic meter (kg/m\({}^{3}\)) & \\  & & Gravitation acceleration in meter per second & \\  & & squared (m/s\({}^{2}\)) & & Rainwater reuse for \\  & [65] & Total head (m) & & single family \\  & [64] & Flow Rate in cubic meter per second (m\({}^{3}\)/s) & & one-story house \\  & & Motor efficiency (\%) & & \\  & & Pump efficiency (\%) & & \\ \hline \hline  & & Electricity input (kWh) (Equation (5)): & \\  & - & Pump power (kW) & \\  & - & Use frequency (\%) & \\  & - & Pumping shut down during maintenance in hours per & \\  & - & day and days per year & \\  & - & Total water consumption (m\({}^{3}\)) which considers: & \\  & - & WFs water precipitation, evaporation, backflush and & \\  & refill (Equations (1)–(4)) & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: MFCS energy in water calculation methods.  
The energy impact calculation method followed the MFCS GHG operational boundaries (Section 2.3) set by TCR [42] in line with the WRI/WBCSD [50] GHG Protocol Corporate standard and ISO 14064 Standard [57; 58] with respect to GHG direct and indirect emissions (Scope 2 and Scope 3).